If you are using managed paths and having trouble connecting to a site using a managed path in SharePoint Designer 2007 try the following steps:
- Check to see if the server you are connecting to is referenced in the Open Site Dialogue Box (ie: http://myserver)
- If so, delete this reference from the Open Site Dialogue Box and try again.
Note I have only received an error while running Windows Vista RC1. The managed paths glitch is known as of B2TR and has already been fixed for the final.