Using Windows Visat RTM, Visual Studio .Net 2005 SP1 and SQL Server Express
SP

When trying to run a website that uses a attachdb file in the
connectionstring I get this error:
An attempt to attach an auto-named database for file
e:\website\site1\app_data\site_db.mdf failed. A database with the same name
exists, or specified file cannot be opened, or it is located on UNC share.

I've tried giving it admin rights and taking ownership, but no difference.
I also get 'access denied' when trying to copy, delete and so on in Windows
Explorer.

Any suggestions?

Stig