Well, you haven't given much specific information, but I'll give you what advice I can. If you enabled swap/virtual memory in the control panel, then up to 128MB of your internal card will be used by that. How much is it showing used? How much should there be? What is telling you this information, and what exactly does it say? Furthermore, if you go into a console (XTerm), type "df" (no quotes), and hit enter, what does it say? Just copy and paste the output in here.
Let me know that, and we can probably straighten this out.