hi,
i'm not sure if this helps.
I've been plagued by a problem that the s3 driver do not support various ibm ramdacs. This is made known by the authors.
if you got the following message in the X startup log, e.g. /var/log/XFree86.0.log:
(--) s3(0): Attached RAMDAC is IBM 526
(--) s3(0): This IBM RAMDAC is NOT supported by this driver, aborting
(EE) s3(0): Ramdac probe failed
Chances are that you are facing a similar problem.
I've posted a kludge/hack which appears to enable me to start X windows
with the S3 driver.
The kludge/hack/patch is on my web site at:
http://home.pacific.net.sg/~goh.andrew/s3_patch/s3.html
note that is is experimental, & i'm not warrantying it.
anyways, hope this helps,
Cheers,
Andrew