Probleme Windows

What should i do? I have a Free wallpaper app in the market and it had been doing really well until recently. I keep getting a bunch of 1 star ratings and really negative comments from  people. I have reason to believe it's my competitor because he has the same wallpaper app (PAID) but it's all distorted and it's getting more downloads than mine!!!  If mine is FREE and high quality and his is PAID and suckish quality then why does he have a higher rating and have more downloads? (He has  a 5 star rating, and i have a 2 star rating....) How could this be happening? Any ideas would be greatly appreciated. Thanks