My player mode crashes on low details but medium lag

MyPlayer mode works well on my girlfriend's computer. I doesn't on mine and I didn't know why...now I read somewhere on the net that this mode always crashes on low player details. I changed mine from low to medium and it worked. The problem is that the game lags with medium player details. I'd like to switch back to low but then MyPlayer mode crashes. It only works sometimes and has to do with certain hairstyles imo. Any ideas?

Anyone?