Simple Fix For Logitech MX5000
My MX5000 had this same problem, almost every time I'd type with my keyboard it would repeat the character I just pressed, from two to ten or more characters. My keyboard also does this in Win XP.
My solution, in KDE 3.5.1, is to disable keyboard repeat. My keyboard no longer "skips," however, it never will repeat, even if I want it to, e.g. the DEL key or arrow keys.
To disable keyboard repeat:
Goto KDE Control Center, Peripherals, Keyboard. Then uncheck "Enable keyboard repeat."
That's it. No more unintentionally repeated characters. There's additional settings I haven't experimented with, which might allow desired repeated keys.
I hope this helps...