Well, does anybody know?

Once you're at the mysql prompt in the Plesk mysql database, how do you delete Frontpage support for a domain if standard Plesk admin c/panel procedures don't work in deleting it?

You may just want to delete all "_vti" and other "_" directories directly.

Ok, I'll try that. Thanks.

And don't forget about the domain.com:80.cnf in the /usr/local/frontpage directory.