"Changed" shell32.dll

Last couple times I've run AVG (free) it's shown the system32\shell32.dll as "changed". No virus detected and all else normal. I manually update AVG daily. While I trust AVG, and it's never found anything, I still have concerns as to what has caused the change. Computer is behaving normally - no slowdowns, etc. Is this something I should be concerned about? And, if so, where do I go from here? I'm running XP with SP2, Athlon 64 3000+, 1.5GB, connected to internet through router and external firewall. Also use ZoneAlarm as well as SpyBot and AdAware. Thanks in advance, for any advice.
-SgtRon-

 

Thanks, Halo. Matter of fact, I had updated Windows recently. The suggestion in your included link worked for me, too. I didn't think it was anything serious, but one never knows. Once again, I'm indebted to the guys at MG!