Okay... bleh, this is a tricky one. No promises that this fix will work, but it will at least eliminate one big question about it. Can you try downloading the official update again? Beta updates are still unlikely to work for you, but the official 4.021 should work if it was a timeout issue on the server host (and if that's true, then I'll have to go back to rackspace support, who said it wasn't). On the other hand, if it's NOT a timeout issue on the rackspace side, then it must be a timeout thing in the WWW class, which will be kind of a hard roadblock for a while, I expect. :/
So I'm hoping it's some sort of server setting thing. What I've done is switch that one official update over to MediaFire, where we have to pay for bandwidth but where there shouldn't be any timeouts.
Let me know how it does for you, hopefully that's what it was! Fingers crossed.