If the SuspendTime option is enabled, X will fail to start indicating that it can not process the option. The other power saving options (StandbyTime and OffTime) appear to work. The README.S3 documents the SuspendTime option.
I am unable to find any reference to SuspendTime option in the /usr/X11R6/lib/X11/doc/README.S3 file that is included in XFree86-3.3.2 or XFree86-3.3.2.
Ooops, my mistake. The *Time options are documented in the man page for XF86Config(5). The man page XF86_S3(1) refers to having to specify the "power_saver" option in order to use the *Time options. In addition, this used to work flawlessly in RHL 4.1 for i386.
What exact type of S3 chipset are you using? It also says in the XF86-S3 man page: The suspend level is currently only supported for the Mach64 and for the 732, 764, 864, 868, 964, 968 S3 chips. It also states that it is considered experimental so it could be possible that your card is not yet fully stable.
Please feel free to reopen this bug once you have obtained the necessary information requested.