This issue has been troubling for about a year now. I have searched using google, but did not get any relevant solution. PC is Compaq Evo (nearly five years old), and monitor has recently been serviced by a technician. He says it is quite fine. OS is XP-SP2 (fully patched), AVG free, AVG antispyware, ZA free, ProcessGuard. AVG AV & antispyware updated daily. Safe browsing habit. Also use spywareblaster to restrict notorious websites. Problem does not happen in safe mode. However, it occurs in normal mode, sometimes after monitor gets up from "turn off" state. The active app window (e.g., Word) will suddenly go a bit out-of-screen horizontally, and then revert back to normal (after delay) - however, the delay factor is variable from few to several minutes. Intel graphics driver has been updated. Shall appreciate leads to troubleshoot.