I have the same problem, except the timings are different (for me the game freezes for about a minute every 10 minutes or so). I didn't have this problem with 0.55, it seems to have been introduced with 0.57. I usually play on servers with 40+ people on, not sure if that's relevant. I had thought it was due to my hardware being insufficient (Q6600 2.8ghz, 4bg ram, GTX560).