Here's a link explaining how someone can exploit those things, and I'm posting it in the hope that you open your eyes and start avoiding using Frontpage Extensions and hosting your stuff in servers with it. For those that aren't interested in reading it, let me leave you with just a quote:
The FrontPage is a wonderful world full of unexplored exploits and vulnerabilities. Its a shame more time hasn't been spent exploring this more. It also goes to show that the more we try to close doors, the more software vendors open up new ones. Forget BO2k and NetBus, Microsoft did a much better job.