I recently bought Killing Floor through steam on my Ubuntu 12.04 machine. The game runs fine, but I am puzzled at one problem, my perks won't upgrade. Countless times I have been playing on Multi player Servers (Unmodified Servers), and I have reached Sharpshooter lv2. Only problem is, at the end of the map, my perk always goes back to lv1 (39 head-shots). I have had the same exact problem with levelling the berserker. When playing on single player, SOMETIMES it will keep the stats, (maybe 20% of the time). Any help would be much appreciated, as I am tired of levelling up to sharpshooter lv2 over and over.