Tested on Chrome 26.0.1410.64 m and the problem still exists.
Don't have IE10 in front of me, but tried on a nightly before beta and looked at the code and it looks like it's fixed.
Very troubling that 4.2 made it into release with this bug, let alone beta without a full fix. Hopefully Sencha realizes how annoying this bug is and gives it priority.
someone found a solution for this bug?
Tried with the latest nightly beta ext-4.2.1-20130424-beta (ext-22.214.171.1247) and the problem is still there in Chrome 26...
We have workarounds but still long for an official fix...
I've tested on some of the nightly builds of 4.2.1 this week and the tooltips have really been tightened up. I no longer observe width problems with Chrome.
Of course it's Sencha's call when this fix from 4.2.1 will be made generally available.
This issue has been fixed and will be available in the GA release of Ext JS 4.2.1
Ext JS - Development Team