I have utorrent but recently every thing i try to download wont download!!?

i tried to download like 3 or 4 things yesterday and nothing worked. they all had alot of seeders too. when i go to download it it says on utorrent that it has 0 peers and 0 seeds! its agravating! the availability bar turns red and the little arrow next to the beginning of the name turns red too. please help! everything was working fine until about a week ago