I have seen a very similar problem.

Running NetBSD 2, without NFS.
The keyboard goes dead - but I still have access via a mouse.
Telnetting into the system and doing a top indicates the X is using 99% of 
the processor. I use kde as the window manager.

Killing X allows the keyboard to respond again - but within 10 minutes or 
so - the keyboard again ceases to respond.

Mark


At 07:22 PM 9/12/04, Martijn van Buul wrote:
>I've been having lockups on my laptop (running 2.0_BETA) too - having
>/usr mounted softdep, no NFS.
>
>I'm having issues with my desktop (Running -current) as well (A
>keyboard which wants to play dead every now and then), but it seems to
>be X related (Shutting down the X server usually fixes it), and
>somehow KDE seems to trigger it moreoften than a plain blackbox.
>
>But I don't think they're related.
>
>--
>Martijn van Buul, martijn.van.buul@gmail.com