1.5.622 Javascript problems with FireFox V33 (prototype.js)

Hi there.

Am I really the only one experiencing Javascript problems in UI5 1.5.622 after upgrading to Firefox V33? (Previous versions of Firefox works well)

The problem occurs sometimes after changing a condition in PLEG when I press the SAVE-button. I don’t know how to debug these things and I have really no clue about what to do about it. Of course I’ve tried running FF in safe mode, the problem persists.