Well, I hop into a server that's got a decent amount of population on it... I start playing, and all is going well ... then after playing for like 2 or 3 minutes ... I get a lovely error ...

I'm still connected to steam at that time ... I've tried restarting steam numerous times, to no avail ... currently the steam friends network is down supposedly... but that shouldn't matter for this right? ... not to mention the rest of the players don't seem to be affected by the same thing.
I have also tried shutting down steam, deleting the 3 files that sometimes get corrupted, and restarted steam...which of course re-downloaded them, join another server, and the same thing happens.
I also have attempted playing on both VAC and non VAC'd servers ... just to try and see if that was the issue.
Any clues as to what's going on?