Yes, I expect the new event triggering logic to be the cause of the slowdown. In two other areas I had manually called trigger() during a mouseover event. Whenever my mouse passed over that element, my machine froze - cpu pegged at 100% for several seconds. This was also while I was running that old FF profile.
After reading the upgrade docs, I added a stopPropagation() in my event handler, and that solved the problem. My guess is that this is a similar issue with my initialization. Over the weekend I will assemble a test case simulating the things our app does on startup. I'll try to determine the root cause and post to the list, along with the test case. -Loren
