Freezing when the level is changed

Hi folks! I have some strange problem.When I join in server and after we finish the level and it loads the next one my game freeze.In 10 games only 1 game is fine and it loads next map.The other 9 times it stops.Its not from my PC because I play on highest settings without any problems,low fps,lag etc.How I can fix this freezing?
P.S. Sorry for my bad english.