HELP - weird keyboard and menu problem

My iMac was acting a bit funny for a while, it would ignore the wired keyboard for a while then after pressing a couple of keys it would work normally until i left it alone for a while, then id have to repeat the process again.

that was until this-morning, When i got to it the keyboard didn't work at all, so i booted into vista and the keyboard worked there, booted to a small emergency OSX disk i have (10GB HD) and again it worked fine, then i booted back to my main 10.4.10 partition and the keyboard still didn't work. I ran software update and was asked for my password, strange thing is it accepted keyboard input for my password and stopped there. Because the clocks changed i went to check that the time in the menu bar had updated and it was gone, along with everything else that usually lives up there on the right with it, sound, connect 360, airport & bluetooth. Spotlight is sometimes there and others not, you could actually say it flashes on for about a second and off for about 2.

When i try and add stuff back in (e.g. sound) i check the box and it immediately unchecked itself.

I've unplugged everything apart from my mouse (mx-1000 laser) and Keyboard (imac standard), repaired Permissions, restarted, even defrayed with idefrag and nothing, no change.

Someone PLEASE help!

on my wife's mini at the mo'

 

Funny thing!?!

Keyboard seems to work in certain Rosetta apps. Menu still screwed

 

any one any ideas on this one

it accepts keyboard inpot on passwords, and rosetta apps (inc universal ones forced to open using rosetta) and i also noticed that on long windows it constantly scrolls back to far left.

im thinking about going out an dgetting an external HD backing up and starting again, but i'd like to avoid it if i can.