I have also thought it has to do with the AV settings, but I have not been able to figure out how to tell McAfee how to bypass SE files.
I was just wondering if anybody else ever saw this when not on a network.
Using SE V18.
When modeling assemblies if trying to save, a "file could not be found" window will pop up and the file to be saved will disappear in the directory. In it's place will be a .tmp file. If I rename the .tmp file to the correct file name and extension I can work on the file...