Hi I want to upgrade my memory and the module already inside says DDr500-pc4000/512. I have looked to get another chip the same or even 1 gig but cant find any. On novatech they do pc3200 or pc4200 then its DDr2 stuff. They did reply to my email saying they dont sell this speed memory. (why not?) If I cant get what I want which ones can I use with whats already in? Thanks. Asus mobo with intel 3.6 processor.