Hello. I don't know how to post bug. So I'm writing it hear.
Avast 5 Free Edition with disabled active protection prevents starting an Eclipse. I've tried Eclipse (x64) versions 3.6 and 3.7M5 with JDK 6u24 (x64), 6u22 (x64), 5.0.22(x64). Operating system is Windows 7 Pro Russian x64. I can'not write the version of Avast, because I had to delete it to understand that it was the cause of the problem. But Avast was updating every day so I gues it was the last version.
PS Sorry for my awful english.
PPS I hope this information would be useful for making Avast better.