This is more of a "Gotcha" that anything else. I discovered this really annoying thing today when I was playing with trees [In the latest version of Ext 2.0 from SVN]. I'd drag a node around, only to discover after the drag, the tree was disabled and I couldn't click on anything. After a few hours of traces and logs, I discovered that this line wasn't being run:
The defer was failing for some reason, which resulted in the tree not being enabled again, and all clickages failing, so I tried debugging the defer method, only not to have any traces and logs appear....strange....but I finally discovered the issue, prototype.js!
I had the latest prototype included, after the inclusion of ext-base.js. The latest prototype features a "Function.prototype.defer" method as well, which has different parameters to that of Ext. So that means the above defer was calling the prototype version, not the ext version.
So there you go, just thought I'd throw that out there.