Failure to power down kernel 2.6.9 Fedora 2 on IBM T21

Hi,

   For all versions of kernel 2.6.9 (but not 2.6.8 or
earlier) when I select shut down / power down on an
IBM ThinkPad T21, the last message displayed is
(Something like) acpi_power-down. However, the display
stays active and to shutdown I have to press the power
button twice. Once to "restart" the machine. Twice to
power-down.

Any ideas?

Clive