Limewire using way too much CPU
 

My limewire is using between 40-50 CPU even when its not downloading, and when I go to preview a song / alt-tab out of it, it will go all black and lag up until the comp can catch up too it. This is a new computer I am using, and my old one which wasnt near as good as this it only used like 10 CPU and never lagged like this. I dont have any viruses or anything, does anyone know whats going on?