Typing sometimes not registering

My Sony Vaio vgnsz660n misses keys often. I don't think it is hardware because I had a VGN Vaio before this, which had the same problme, and Sony checked the hardware and found no issues. Then they let me replace it with this Vaio, but it is still missing lots of keys. As I type this I have to go back many times to retype missed keys. I have lots of programs open, but also have 4GB Ram, and Centrino Duo, and the problem exists with minimum programs open as well. I never had this problem with my slower computer using Vista. When the computer is busy it pauses, but always remembers what has been typed. Not so with this faster, newer computer using Vista. Anyone know what might be the problem?

 

crumbs & other accumulated cruft under the keys perhaps?

a guide to cleaning: http://www.computing.net/howto/simple/keyboard/

 

No. Like I said, I had this checked ot by Sony Support with my last Vaio, which had the same problem, and they didn't find anything like that, or any hardware issues. Also I vacume my keyboard and it is never that dirty anyway.

 

can you take it in to the support guys and show them?... it certainly sounds like a hardware fault of some description.