Dancing cells in notebook

[fonnesbeck]

I'm occasionally getting some bizarre behavior in the IPython notebook currently in master when editing Markown cells. The focus on various cells changes rapidly, and I completely lose control of the notebook. I've yet to be able to repeat it consistently, but it has happened more than once. Here is a movie of the behavior. The behavior goes away if I refresh the browser window.

Running Python 2.7.5 on OS X 10.9.1 in Safari 7.0.1.

[jdfreder]

Just watched the clip, that is an awesome bug.

[ivanov]

I've also seen this one, but thought it was due to a misbehavior of my forthcoming vim keyboard shortcuts keyboard shortcuts

[juhasch]

This looks like the same behavior I also see (issue #4999). If I revert the mentioned PR, it looks OK again.
One way to reproduce it here is by clicking outside of the browser window once and then back into the browser with a right-click:
http://www.youtube.com/watch?v=jkGgwL1T-1k

[fonnesbeck]

One pattern I've noticed is that this seems to happen when the engine is busy.