My pleasure, Dave
I am sorry to hear you found no solution there. Another thing that has just crossed my mind: have you tried playing with AGP drive strength on BIOS? Appendix F of the Linux driver README says:
Many Via based mainboards allow adjusting the AGP drive strength in
the system BIOS. The setting of this option largely affects system
stability, the range between 0xEA and 0xEE seems to work best for
NVIDIA hardware. Setting either nibble to 0xF generally restults in
severe stability problems.
If you decide to experiment with this, you need to be aware of
the fact that you are doing so at your own risk and that you may
render your system unbootable with improper settings until you
reset the setting to a working value (w/ a PCI graphics card or
by resetting the BIOS to its default values).
(kinda scary, but since things are not working anyway... worst thing that could happen is forcing you to reset BIOS directly on the mobo's jumper if things go really bad).
Also, I would suggest trying out latest kernel (2.4.20), which is the one I am using right now with 4191 driver (although 2.4.19 worked just fine with 3123).