I found some problems in the IDE of LC 5.0.2 on OSX 10.7.2:
1. double-click on an object does not open the script editor
2. the script editor opens always at the same position and size, even when I put it on the left and make it smaller the last time I used it.
3. script of card opens only if i opened a script of a button before
4. for searching in the dictionary I have to click twice or more times into the search field, before I can enter an text, when the dictionary was closed before.
5. the debugging does not stop at a stop point.

I hope it will help to get a 5.0.3 without the bugs.