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Mouseover and mouseout events won't trigger when mouse moves too fast?

I wrote a live demo to show this problem:
http://cssdeck.com/labs/wcczap11
If you move mouse fast between the blue, red and green areas, you will see red 'y' logs are not appear between x and z logs, which means you can't get the red area mouse events.
This is what I want:
But when mouse moves too fast:
I just want to know is there a way that no matter how fast I move the mouse the result will always be the same with the first image?

I'm not completely certain if it affects javascript, but different mice have different polling rates (measured in Hz) and if your mouse is 1000hz and you move 1000px at a constant velocity you should pick up every pixel.
However in reality we move the mouse very fast to begin and slow down as we approach a target to improve accuracy. meaning the first 700ish pixels will have been moved faster than the 700hz could poll and so you're missing values where the mouse moved more than 1px in 1hz.
That's kinda of a dumbed down version (mainly because I don't know everything about it) but basically small-hit-targets are prone to being missed by mousing events.
You could attempt to make target-areas larger, but it still won't fix everything :)

The problem here is a simple one.
The events aren't being "lost" as such. They are never actually triggering in the first place: due to the speed of transit, at no point is the browser picking up the pointer as being "over". If that's the case, then it can't trigger "out" either, as it was never viewed as being "in" in the first place.

It doesn't get lost. It comes and goes but you cant see because you move the mouse too fast. And in your example it is not lost.

Calling a callback that takes too long to execute can cause the browser to skip a poll until the next polling tick (Have you ever seen the [Violation] 'message' handler took 326ms console messages?). You're using jQuery to attach the event handlers (and I don't know much about jQuery), so there's a chance that the event handlers aren't passive.

Enable mouseup / mousedown but prevent click behavior

I have a data visualization here (the second one):
http://mikeheavers.com/main/work
If you click on the circles representing skill fields, it reveals inner green circles with the particular skills. If you hold down on the green circles representing the skills, they animate, grow, and then shrink back on mouse release. However, if you simply click on the circles, they grow, but do not return to their previous size (the mousedown is not registered I guess) - which results in a circle that will constantly get bigger each time it is clicked.
Is there a way to prevent click behaviour, either through d3 or through Javascript / jQuery? I only want mouseup and mousedown.

I'm observing different behavior than what you described.
If you single click a circle, it doesn't matter how long the click is (whether it's held or not), it returns back to its original size.
If you click a circle repeatedly and quickly, this is when it starts to grow and does not return to its original size.
If you hold down a circle and then move your mouse outside of it, it both stays pink and doesn't return to its original size.
I think attaching a simple .on('mouseout', handler) to return spheres to their original size will solve the last issue, which is pretty glaring, and any missed mouseup events due to moving outside. You can also attach a mouseup to the whole document (d3.select('body').on('mouseup', handler)), which will catch any such event; then you would just need to record the last sphere that was clicked.
Additionally, to fix your original problem, you can make sure that mouseup events are triggered by adding e.preventDefault() in the mousedown events. This will prevent fast clicks from turning into double-clicks or other events by the browser.
Other posts that discuss these issues:
mouseup event isn't always triggered
mouseUp event on drag

HTML document - can't prevent object dragging

I'm working on a web app that's available for testing on:
"http://83.150.87.220/dropbox/HelsinkiViSeZip/Jatkasaari"
It is used (mainly) to zoom in on an image and pan that same image.
Once the document loads and the central image becomes visible, you can mousedown + drag to either zoom in/out on that image or pan it.
When pressing the mouse button down, you'll notice that the image turns blurry and that an indicator (png image) appears just under the cursor. That indicator shows you how to move the cursor in order to select an action (zoom/pan).
Everything works just fine in Chrome, but in FF, once you mousedown for the second time on the image and start dragging the cursor, it seems that the indicator (the png image I mentioned earlier) drags along and messes everything up. This seems to be pretty much the default behavior for clicking-dragging images in any browser. But it's very weird, since on the first mousedown+cursor drag combination, everything works just fine. And not to mention that I made sure to prevent the default action for images:
$(document).on('mousedown dragstart', 'img, a.icon', function(event) {
event.preventDefault();
});
I'm all dried up in terms of ideas on how to find the problem, so I'm going out of my mind...Can anyone help?
Thanks in advance!

You could try setting it as a background image inside of a div container or something similar and just show/hide that instead of using an img element. That way you won't be able to actually "select" the image with the cursor but everything should still work if it's driven by javascript.

I was facing a similar problem and it seems that it need to also return false; to prevent the browser default behavior.
Here is the fiddle

Javascript IE mouse events restricted to original recipient?

I have an info overlay that works great in Chrome and FF. It is a div containing a table (for border image layout) and then a central content div. I trigger mousedown on the appropriate border table cells.
Once this happens, a different div is brought to the front with z-index, and that passes along the mousemove and mouseup events to handle dragging the info bubble around. Once the mouseup is fired, the info bubble puts the "event" div back to where it was.
I also follow the same process for dragging the lower right corner of the bubble to resize it. Again, works in Chrome and FF, but fails in IE.
IE seems to be restricting the event triggers to the info div. If the mouse manages to move outside the div (from dragging faster then the events fire/update), the info overlay no longer receives mousemove events. However, if I move the mouse back over the overlay (without releasing the button) it continues to receive mouse events.
Edit: In creating some example code (the current functionality is split across several JS modules), it worked in IE. As soon as I find the difference between my example code and the actual code, I will update again.
Edit/Answer: (SO wont let a new user answer their own question in this time span...)
Still not sure what the actual problem was. (If you ask me, a div with a z-index of 100 should be receiving mouse events just fine?)
My solution was to fix my mouse event handling such that I could attach my mousemove and mouseup to the parent div (as should have been done in the first place) for all dragging/resizing behaviors I wanted to set up.
The problem was due to a newbie approach to the events and having stopPropagation() in too many locations preventing me from taking such an approach. (I wanted text, etc in my info box to be selectable).
I adjusted the code so that my text containers only had to stop propagation on mousedown instead of all the mouse events.

mouseover fired with mouse still and element moving

I am in a situation where I need jQuery's mouseover event to be fired when an element (in this case an image) moves under the mouse, so unlike the common situation is an element that is moving, not the mouse.
Do you know of any library/gist/technology that could help me in this sense?
I've tried with flash but with no luck, is this something than can actually be done?

You can track mouse position by binding a handler to mousemove on the body, and calculate after every move of the image whether the pointer is over it.

I ran across a similar issue. In my case I did a "good enough" workaround by keeping track of the time the mouse last moved and then in the mouseover handler seeing if the mouse had moved recently -- within 30ms of the current time. That way I can bail out in cases where the mouse didn't actually move, but I don't have to test the hitboxes myself -- something very hard to do right and fast, and fortunately something I can leave to the browser by doing this.