Peter
Just wanted to let you know that I finally got around to upgrading to 5.0.2 again (after backing up the data of course). I think I found what was causing the JavaScript errors reported above.
In your upgrade you are now minimizing the JavaScript according to your upgrade sheet. We use PageBlaster in our installation so when I noticed that particular upgrade feature I added the following to the PageBlaster config file:
< path pattern="DMX" excludeFrom="JSMin" />
This prevents PageBlaster from trying to minimize already minimized JS code, which will cause nothing but problems!
Everthing seems to be working fine now.