ouch
You were right there is a evil bug in 6501
We've just fixed it, i hope it solves your issues.
You can either decide to redownload the full thing or just the exe
which is here
http://plogue.com/bidule/65011.zip
(the new version should read 0.6501.1)
Please inform us of more problems directly on our phorums
as i might not be able to monitor all forums for a while.
Cheers