Computers doesn't power off

[Piers Kittel <debian@biased.org>]

Upgraded to the 2.4.27 kernels on both my work and home computers but 
now I find that they both don't power the computer off automatically, I 
have to push the power button manually when the computers has shut down 
- how to make it turn itself off now?

Thanks very much for your help in advance

Cheers - Piers