I updated on my PowerBook Alu G4 to YDL 4.0.1 with and use kernel 2.6.10
the sleep feature works in general. but after awaking the USB ports don't work any longer. These are the entries in /var/log/message when going into sleep mode - when awaking there is no USB entry.
Mar 15 23:12:34 aurora kernel: Apple USB OHCI 0001:10:18.0 disabled by firmware
Mar 15 23:12:34 aurora kernel: Apple USB OHCI 0001:10:19.0 disabled by firmware
Mar 15 23:12:35 aurora kernel: ehci_hcd 0001:10:1b.2: USB 2.0 restarted, EHCI 1
.00, driver 26 Oct 2004
Mar 15 23:12:35 aurora kernel: usb 3-1: USB disconnect, address 2