I have run into this same error message, "Cannot Open Resource File" when saving files. These files are saved on our Windows 2003 network. I think ID is trying to open the resource fork of the file, and timing out or running into some other error. Lately we have had really slow network access times, so I think that might be part of the problem.

Anyway, our solution was to go to InDesign -> Preferences -> File Handling. Uncheck the box marked “Always Save Preview Images with Documents” and close the Preferences.

After doing that our network files have not had the “Cannot open resource file” error. I have not seen this solution anywhere else.

Darryl