If your client is updated, you cannot connect to servers that are not patched to the same level.
Unfortunately this is not always true. It depends on what was changed and if the internal build number was changed during an update. There were a couple of updates already where you could play on a server that was not updated yet, with several things missing accordingly.
The inital update was actually released with a game breaking bug again, making it impossible to play for a big group of people, with a debugger windows coming up when most of the game keys were pressed. There was a small silent update a short time later, that fixed it. Again, how that one slipped through QA if there is any, I dunno.
Anyway, the only reason I'm asking is because I didn't feel any changes in the scout department and Cruel didn't see a difference in the Spy department apparently. Might be, because I don't play with the changed items usually or that the changes weren't as big as I thought. Or our server didn't have the update...
Yep thats true (applauded) I forgot to mention the build number and I 'assumed' the build number was updated in this update...