If I press any of the movement keys, (e.g. Home, Page Down, up arrow)
a full screen print (same effect as pressing Prt Scn) is copied to the
clipboard when I use any external (wired or wireless) keyboard (PS2
keyboards with PS2/USB converter). I tried uninstalling HID Keyboard
Device which as expected temporarily disabled the external keyboard,
but the print screen problem continued after a restart. If I use the
movement keys on the external keyboard?s numeric keypad (with Num Lock
off), or use my laptop?s keyboard, I don?t get the problem.
I use Windows XP SP2 on a Toshiba Satellite laptop. I can't see any
suspicious programs running in the background. The problem occurs when
pressing the movement keys in all applications including DOS. It also
happens in Safe Mode (the following were running: taskmgr.exe,
ctfmon.exe, explorer.exe, svchost.exe, lsass.exe, services.exe,
winlogon.exe, csrss.exe, smss.exe; these all seem valid programs). I
know I can use the Office Clipboard to store multiple copies but don't
want to rely on this.

Hello,
we have the same problem when using the USB/PS2 converter labed as
U-PS2-1-K41 by www.ccando.com. It occours exactly as you desribed on
WinXP Sp2 and Win2000, and only with this adapter. When switching the
NumLock off, the problem disappears in most cases, but not for
<shift-insert>. Does anybody know more?

Chris

Thanks for your comment Chris. I didn't realize that NumLock had an
effect - leaving NumLock off fixes most of the problems.
However, doing a shift arrow with NumLock off causes the clipboard to
fill with screen images indefinitely until NumLock is turned on again.
I think I may go for a USB keyboard and it sounds like that doesn't
cause a problem. But I'd appreciate anyone else commenting, or
suggesting a fix.
Many thanks, Clive

Chris, 
Another update on this. I appear to have fixed my problem my using a
different USB-PS2 converter; my original one that gave the clipboard
problem was a doubler (one USB going to two PS2 ports). I now use a
single USB-PS2 converter for my keyboard and can use movement keys
without it copying a screen image. I had incorrectly believed that
this must have been a software issue before (e.g. drivers).
Clive