I'm having an issue with the PutAttachment in an App Engine. I can get it to work when the file is on the local drive (C:, D:), but it fails when the file I want to copy is on a network drive.

I'm doing a FileExists, so the process does find the file, and the process does end successfully with a return code of 0, but the file on the network drive doesn't get copied.

Any ideas?