windows explorer acting up

This is something new happening the last few days. When I open either My Documents or My Computer, or when I right click on the Start button, Windows explorer doesn't open, but something strange happens, whatever windows I have open get shuffled around on the task bar at the bottom of the screen. It also happens when in windows explorer (It does open sometimes) I try to open a folder, or right click on it to look at properties for example. I'd say this behavior happens 2/3 of the time. Once a pop up showed up for a second, and I had time to read one word in the to pline: debugger. But there was no time to get the rest.
I have a Lenovo G530 laptop with XP SP3 and all the 00's of updates that come around almost everyday.
My AVG antivirus and my Advance system care are up to date and neither detected anything.
Any idea of what's causing this and what the fix might be?
Thanks

 

As Arie suggested, this problem is now posted at http://www.windowsbbs.com/malware-virus-removal/106148-windows-explorer-acting-up.html
Should I close this thread?