We have the same problem. Is there a JIRA entry for this bug?
I've filed a bug...
However, they appear to not be able to reproduce in in their development build. I'm not sure if that indicates its been fixed or if something else in the environment is different. I'm running MyFaces 2.0.5 which I've found occasionally has bugs with Richfaces (since I don't believe Richfaces is tested with MyFaces). Feel free to add your experiences to the bug.