Has anyone had any luck getting ADI SoundMax AD1981B sound chips (I believe an AC97 codec) working in Windows 98?

I've recently been tinkering with two very late IBM systems (P4 era) that I'd love to get Windows 98 running on, but although there are official drivers for the ADI SoundMax for these systems in Win98 from Lenovo (other OEM drivers wouldn't install - different PCI IDs?), I just can't get it to work on either system, with any available version of the driver. Every time I get this error:

"The NTKERN.vxd, MMDEVLDR.vxd device loader for this device could not load the device driver (code 2)"

The two systems are a Thinkcentre S50 with P4 socket 775 and i915 chipset, and a ThinkPad X40 with a Pentium M and a i855 chipset. I've used the modified "Loneranger" Intel INF files for the chipsets (or at least tried to), and I'm using a GeForce FX 5500 PCI on the desktop system to get around the lack of graphics drivers.

The desktop 915 based system does seem pretty stable in Win98 otherwise, although there always seems to be a "Direct memory access controller" that also has a driver couldn't be loaded error (one of two, the other instance seems fine). The X40 does seem a lot more problematic in 98, but it definitely feels strange they both have the same driver error with the same audio chip!

I thought I was on to something when I spotted the readme of one version of the drivers said DirectX 9 required - but no luck!

I suppose I could install an SB Live in the desktop system, but that would mean finding a PCIe X1 graphics card with 98 drivers! (Maybe an ATI X600 low profile in a X1 to X16 adapter might work?)

Any suggestions for dealing with these errors?