Dunno unless it's that evil number of posts you have, 666. Need to make another real fast.
Seriously I honestly don't know. Every once in awhile folks will ask the same question. I cannot duplicate the problem. Even when I log in as them it doesn't happen. My best guess is you're having a problem with your connection thru your ISP to the GBO server.
Some while back I had a tree that grew up too big in front of my satellite dish and I was getting that message way too much. Matt checked things out for me and told me the tree had to go. Man did I hate to see that tree go as I loved my river birch tree and where it was. but he convinced me. We cut it down and I've not seen the message since.
It's not necessarily a problem with your ISP or my server but with the chain of connections you have to go thru to get from one to the other.
I send and receive many PMs daily and members as a whole send and receive hundreds daily.
Wish I had a better answer but I honestly don't. It's not your account and for sure it's not the GBO server. Those are the only two factors I have any control over.