I just finished up an interesting week attempting to upgrade
an old 486-33.  I installed a clone 486 VLB motherboard,
Number 9 VLB video (S3 based), and second IDE hard drive.
Warp 4 installed fine.

First Goose:  Attempting to install the IBM-supplied S3 drivers.
The system would die (monitor goes into power save) with any
resolution above VGA.

First Goose cooked: installed the OS/2 drivers that came with the
card.  Worked great; instructions were clear and detailed to a
fault.  Have since updated to newer versions from www.nine.com.

Second Goose: The modem and the mouse would not play nicely
together.  After checking DejaNews, the IBM tech files, etc.,
I did the following:
Put the mouse on COM3:, IRQ5, via the RODENT.SYS driver.
Put the modem on COM2:, IRQ3, via SIO.
Disabled COM4:  (thanks, S3…)

No matter what combination of these things I tried, anything
sent out to the modem would freeze until I moved the mouse!
(By rolling the mouse back & forth, I was able to connect to
a bbs, but it got tiring…)

Figuring on a hidden conflict, I replaced the #9 with a standard
ISA VGA card.  This time, the entire *desktop* would freeze until
I moved the mouse. (that made for an interesting shutdown…)

Second Goose cooked: in a final desperate act, I replaced the
486 VLB motherboard with another (practically identical) one.
Everything now works perfectly.

The interesting thing is, I went with the first motherboard because
it had a much better manual, and the workmanship was a little
better.  The board that works has cheesier connectors, a cryptic
little manual printed on newsprint, and one less ISA slot…

–Gene