I've seen the same thing.
I've managed to get around it by deleting some of VV's preference files. It was one (or two?) of the three main .plist files in ~/Library/Preferences (I forget, does VV have its own folder). I don't remember exactly which one. I'm not on my home Mac right now, so I can't locate them or name them specifically.
(The problem appears to come back repeatedly, too.)
[edit] I believe it's com.ibm.vv.VoiceCenter.plist, but it could be one of the other com.ibm.vv entries.