This is getting to be very annoying! Does anyone know wtf! this is all about. I get all the way through loading then at the last possible second it disconnects for unknown reason. 
I did a search of the forums before posting but didnāt see anything in the first 100 posts about this problem.
check your cd key. i had same problem, uninstall, reinstall sorted it
for me.
good luck 
What happens when u hit reconnect? does it do the same? are you able to get onto any servers?
This happens occasionally to me when Iām connecting to a server and itās usually when the map has just changed (eg. you get the gamestate from the server saying itās currently the oasis map, but the map has finished, and while you are loading oasis the server has moved onto battery. So it all gets a bit confused and disconnects)
Pull down the console and scroll up to see the actual error message. Just scroll up until you see the connecting attempt and see what follows.
RK
it seems to result from a lot of PB kicks in ET for some reason, anything from badname to cvars etc it can show unknown reason sometimes :???:
as said best way is usually to scroll up the console and look for the culprit.
i have that shit A LOT to :banghead: .
and also connection timed out :bash:
i think its a bug or something.
i have it since the patch b4 the patch i didnt have any problem :moo:
if thats your game name Iām not surprised, some servers (incl. mine) dont allow āteammateā in names, and if just āetplayerā you might be kicked for suplicate name if thereās already a etplayer on the server.
seemed to work but it always is my last resort. I was having some other problems with the game that forced me to reinstall. (btw, i did take a look at the error message and did say something about punkbuster.)
Both issues seem to be resolved. /cross fingers.
Thanks for the help.