Getting the Pismo to snooze

[Andreas Moor <nospam@bitbucket.ch>]

Hello

How can I get my PowerBook G3 FireWire (aka Pismo) to sleep under 
Debian PowerPC? It's running in woody unstable with the current 
2.4.24-benh kernel with CONFIG_PMAC_PBOOK=y. The /sbin/snooze command 
results in

pmud[298]: initiating user requested sleep
pmud[298]: running /etc/power/pwrctl sleep ac
pmud[298]: going to sleep
pmud[298]: cannot put system to sleep! (Inappropriate ioctl for device)

Any ideas? It used to work out-of-the-box with an unmodified Yellow Dog 
3 install.

Thanks for your help
Andreas