I can't reproduce this with the public beta build (or others for that matter) but will take a look at the crash report log and get a bug filed. Do you see this with any other effects? Does anyone else see this problem?
A couple of questions.
Have you scanned for other VST or AU plug-ins in the beta?
If it is what I'm thinking, then I think you would have done that at some point. This would've created the following file in your application preferences directory:
If you delete that file, does the problem go away?