Ok I know that a lot of people have had similar issues, but from what I've read my experiences seem somewhat different.
I have the issue where the entire hostile team is invisible, but no amount of restarting seems to fix it and there is not the usual accompanying sound glitch.
whilst there are no known issues with my hardware, my internet connection has been known to be very unreliable in the past.
if you need extra, more specific info please ask.

Thanks
Maynard

what is it with games nowadays this game is no Sound, map repeating, and invisible players both teams.

I (q9550 GTX285) heard of this bug - never had it myself - and finaly today my girlfriend next to me (q9300, AMD4890) got it to. When i asked her which players (they were bots in this case) where invisible there was a bit of confusion. The same bots (at least same location visible on my computer invisible on hers) had DIFFERENT names. We couldnt test if all bots had different names but a quick queck on the who-killed-who chat confirmed our suspicion that her client seemed to have desynched with the server - which was running on my pc as a dedicated server - and thus created the invisible entities (in our team and the enemy).

Don′t really know if it helps the programers figuring out this bug, but at least we can now have a look an confirm this behaviour or falsify the theory.