Run lphdisk /dev/hda to prepare the disk and the BIOS for suspend to disk. After your next reboot, you are able to use this feature.
To resume properly (only when you use XFree 3.3.x), you should insert the line touch /var/tmp/reset_B112 in your /urs/sbin/apmd_proxy, section ``resume''. It is for a touch-panel-coordinates reset back to absolute coordinates (seems to be necessary).
Set the following variables in /etc/rc.config to yes: Leave X before standby, leave X before suspend, start apmd.