Random keyboard malfunction - happens in Vista and XP

For some weird reason, some of my keyboard keys of my Asus s96j laptop are acting very strangely.  I don't remember a certain time when it started and I can't recognize any pattern as to when it happens and when it doesn't.  The problem occurs in Windows XP, XP Safe Mode, Vista, and Vista Safe mode (I have a dual boot system).  Here's what's happening:
When I push the I,K,comma,or 8 keys (notice how they are all in the same column), instead of just getting that character, I get extra characters afterwards.  For example, I'll push the k key and it will print "ksfda", pushing "I" gives me "IWREQ", comma gives me ",xvcz", pushing 8 gives me "82431".
There are a couple things that i have noticed:
1) it does not happen every time I push the key
2) It happens in all OS and applications I have tested
3) the characters coming after the desired ones are in the same pattern (column order: 2,4,3,1 from the left of the keyboard in the same row as the key pressed)
4) pressing "]" will sometimes give me "]t", and if done in Notepad, will bring up the "Find" dialog window
5) I cannot seem to remember a specific time the problem started, although I have been defragging, using TuneUp Utilities + CCleaner, and installing lots of new programs lately.

A system restore did not fix the issue.  Is there any way that this isn't a hardware problem?  I don't want to complain to Asus if the problem is actually with a rebellious piece of software or some Microsoft keyboard alias setting that I don't know about.

Thanks,
Andy