We are still experiencing this (or a similar) issue using 3.0.4.
In Firefox (26.0 OSX and 23.0 Windows), the tree scrolls to the center, and no ClickEvent is fired (although the MouseDownEvent does fire)
On IE9 (Version 9.0.8112.16421 Update Version 9.0.23) , the tree scrolls to the center but the ClickEvent still fires.
On Google Chrome (32.0.1700.77 OSX), we do not experience the issue at all.
The problem actually goes away entirely after clicking on an element which is visible in the middle of the tree. Scroll/click works normally from that point onwards.
I've tried getting the sencha explorer working for 3.0.4 in my workspace in order to confirm the problem still shows itself in the simplest case, but am facing compilation issues. I may just construct a simple tree and make it available for reference.