I been reading other posts about this issue. I am testing out ACAD LT 2013 I've narrowed it down the the hatch. If I remove hatching the problem goes away. Not sure why theres no issue with Acad LT 2010 using the same hatch pattern. Tried making the adjustments as per the previous poster suggestions. Turning off the hatch is really working the best
Running Win 7 , 64 bit quad core AMD 2.2 gig processor
4gig ram
Gigbyte MB with on board graphics