In openSUSE 10.3 everyting was fine. Now in openSUSE 11.0 with KDE 3.5.9 it isn't. I tested following 3 ways of hibernating:
1) pm-hibernate
2) RMB on KPowersave and Suspend to disk
3) s2disk /dev/disk/by-id/scsi-SATA_ST9808210A_3LF0ZWFA-part1
and all theses are working fine.

I guess KDE doesn't detect it is possible to hibernate and it doesn't display this option. How can I provide more useful info?

linux:~ # rcpowersaved status
Checking for service powersaved                                       running
linux:~ # lshal | grep power_management
  power_management.acpi.linux.version = '20070126'  (string)
  power_management.can_hibernate = true  (bool)
  power_management.can_standby = false  (bool)
  power_management.can_suspend = true  (bool)
  power_management.can_suspend_hybrid = false  (bool)
  power_management.is_powersave_set = false  (bool)
  power_management.quirk.vbe_post = true  (bool)
  power_management.type = 'acpi'  (string)

It is notebook Acer Aspire 5024WLMi.

Ah, using KPowersave is of course kind of workaround but still I think it should be possible also using KDE shutdown dialog.