This may not work for everyone in this situation but it worked for me. The crash where mp would freeze or the map would load not finish and freeze was caused at least on my machine by a faulty broadcom wireless
adapter driver . i disabled the driver via device manager and the problem seems to have been solved.
my specs
3770k
asus formula v motherboard
16gb dominator gt 2133
evga 680 classified
vertex 4 ssd raid 0