SSL not working on sub-folder Win2003

Hi All - I have SSL working on a site running on Windows Server 2003, but as soon as I try access an asp file in a subfolder, it's as if the file/folder doesn't exist...I get the message 'The page cannot be found - The page you are looking for might have been removed, had its name changed, or is temporarily unavailable.'. If I change the https:// to http:// then it works fine.

I get the same problem even if trying to access a gif in a subfolder - it's as if SSL is being barred from working in sub-folders, but I cannot find anywhere to enable this.

Any ideas? Help would be much appreciated!

Andre