shutdown restarts laptop (and disables kb)

[Firesam]

I am having a very strange (to me at least) problem with my laptop
computer. It took a while until I was able to replicate the exact
circumstances that caused it. Whenever I shutdown the laptop restarts
and does not power off. Just incase that is not annoying enough when it
restarts the internal kb and mouse are disabled. Interstingly enough mot
only that this is not caused by choosing restart (the kb/mouse thing)
but restart fixes it and re-enables the kb and mouse. 

I don't know if this is related but in grub choosing a command line and
typing halt just freezes and does not power off. reboot does reboot.

I can supply (I think) any files/logs etc.. that will help.

Thanks.