Recently I had wiped my pc, and reinstalled m&b. Before my wipe this problem never occured, and it only occurs with warband.
During a game I will usually get random spontaneous ping spikes, which triple my ping for a second. This causes a sudden freeze before resorting back to normal. No programs conflict with my game, and this does not happen with any other game.
It's also very frustrating when your addicted to melee.
If anyone played cRPG and experienced those spikes, they are very similar.