I've played around with it and it happens whenever I do a save as. Whether I save to the network, my documents, etc.

I'll take a look through that link you posted and hopefully I can figure something out. Usually I remember to close out and re-open Excel after I do a save as, so it doesn't matter too much. But sometimes I'll forget and have to redo everything I just did and it's a pain in the rear if I had done a lot...