program slows down then eventually says there is a connection problem
 

when i start limewire it starts fine for about 1 min or so...status bar at the bottom left corner shows everything is fine..then the program slows down the whole computer...downloads start to freeze then eventually an error message appears saying that i have a problem connecting to the network or something or that i have a firewall but i dont have a firewall. what do i do..the program used to work fine but seems to be on the fritz the last couple of days...pls help!!!