Running a fresh install of win98se. I may try xp just to see if that will work but its so odd.

There's that one game that i740 looks nice in, but personally I'd rather run a SiS6326, or an early Rage, heck even early Virge sounds good... I don't know much about the windows drivers for them though, my one i740 is usually not even used in DOS, it's the scratch monkey for firing up unknown AGP boards in case they fry the AGP card. So far it's luck holds...

I also have an i740 AGP (labeled "Fastware" on the BIOS sticker) that has the exact symptoms, on an Athlon XP 2000+ based system with VIA KT266 Chipset and Win98SE.

P.S.
Desktop seems to work ok when booting in XP with the windows preinstalled drivers; but no DirectX application is able to run.
Was able to run Artefact Locator, and Video Mem Tester, and the card checks out ok 😐

I find the i740 to be interesting for how unique it is.
However using one on a PC Chips socket 7 board and Windows 98 FE.....is playing with fire.
Good luck though!

After tinkering in the BIOS, I found the solution to the problem described by OP with the i740:
Changed AGP mode (from Auto) to 1x, and reinstalled the drivers (v4.0), and now it work perfectly!

Ran 3dMark 99 'till the end without any problems 👍