HELP: AutoCAD slows down!

We just got new computers at work. Dell P4 2.8 512 ram 40 gig HD. Wer'e running Windows 2kPro and AutoCAD 2002. After working in AutoCAD
for about 20 to 30 minutes all the commands slow way down, another words if I pick the move command there's about a 5 or 6 second delay from the time I pick it to the time it initializes. If I turn AutoCAD off and then on again it works fine again for about twenty or thirty minutes and then slows down again. I checked the virtual memory settings and they seem right (1.5 times the abount of ram min.). I tried turning off all other programs but AutoCAD and the same problem occurs. Computer has 512 meg of ram which should be plenty. Anyone have any idea what is wrong??
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.