I finally got all 11 computers to update to R15_73 and they are working fine now.  Yes, they told us the first time we called it was an issue with the attachments.  But that was AFTER the tech support guy tried to tell my IT guy it was OUR network.  It was only after my guy said there was nothing wrong with our network and QB tech verified that he then revealed the problem was actually a QB issue on their end.  I love how they always say it "our" fault right out of the gate!