Ghost? Constant freezing, scrolling, right/left clicking,etc

running: windows xp, sp2

Lately my computer has been freezing every 10 (or so) minutes, more often when I'm running more programs. I can usually work without interruptions for 15 minutes if just running 2 firefox windows plus aim, but in most cases I need to run photoshop, have a few folders open, and other programs.

-freezes constantly and only unfreezes when I go into Task Manager and click the program and ''bring to front'' but even then will sometimes freeze again and I have to re do that AND if I let my computer sleep for a little bit, I have to restart it because it wont start up again
-randomly will highlight everything on the page and then scroll down
-will lock on ''fast scroll'' (when most of the screen becomes more opaque and then you can quickly scroll up or down. example: when you click down the wheel in the middle of the mouse)
-randomly my ENTIRE startup menu/bar won't work
-apparently some of my files (since the ghost has come) have been corrupt. I crashed the computer at the film store 3 times when I was tryign to print jpegs. They said they weren't real jpegs, just a bunch of code. but the rest printed ok (saved at relatively teh same time)


I've run mcafee virus scan, ashampoo winoptimizer programs, and hijackthis and have come up with nothing.

-windows firewall and my router's firewall set up (netgear rp614)
-sony vaio laptop with 40 gigs (2 seperate hard drives) with 512 RAM

NOTES: My internet boots me constantly as well, more often at night (every 5 minutes)

and I spilled a little bit of soda on my keyboard a afew weeks ago and cannot use the S or D key. So I use a wireless keyboard.


THANK YOU FOR ANY HELP POSSIBLE. I AM SLOWLY DYING OF AGONY.