In several EAP builds I have noticed the following problem:
Whenever I do some changes to a file, changes are highlighted in the editor sidebar and in the filename. But when I hit CTRL-S, switch to another program or wait some time, the highlighting is gone and the file appears as it didn't change.
I've noticed this problem in all EAP versions I tried after 5181 (where it works).
I guess it is already logged as bug 7532.
In the latest EAP build (5383) I have noticed a different problem:
If I do "Version Control" -> "Commit project" there is a dialog box saying "Analysing changes" for +- 5 minutes, after which it says "No changes detected". I use the ClearCase plugin.