acceptable win rate on MTTs?

I guess I just got lucky on one site, I placed in three MTTs and drew out about $2000 to get me down to the $200 I started with and then boom, no more wins and now my $200 is half gone!! I had played 3 of the $20 tournaments I had placed in before, then a $10, then dropped to $5 and now I am afraid to try again. So that was about 10 tournaments with no cash. What would be an acceptable win rate? Should I quit until I get that $100 back? I can bring it back with SNGs, slowly. How does this experience compare with others?

You are playing to big of buyins for your size of bankroll. With the huge fields of MTT's the variance is much greater and therefore you need a larger bankroll to be able to handle the swings. It's probably good to have about 50 or so buyins for a tournament which means that with a $200 bankroll you should be playing $4 tourneys.