I keep getting exception 0E's in vxd ---

A quick search of usenet (or even a long search) results in hundreds of
posts about this "vxd ---" error, but little or no solution. This
problem does not appear to be in the Microsoft KB (either that or the
search feature is incapable of searching for "---" in the query string)

The closest I have been able to come up with by searching usenet is a
suggestion that the error might be caused by the dimms overheating.

The exact error is as follows -
A BSOD with... An exception 0E has occurred at 0028:c00xxxxx(varies) in
VXD ---. This was called from 0028:c00xxxxx(varies) in VXD ---.

The error occurs when I am running Virtual Dub
(http://www.virtualdub.org/) during encoding of XviD
(http://www.xvid.org/) avi files. It also occurs while playing Scrabble
online with Wordbiz (http://www.isc.ro/)

The problem is still present if all non-essential programs and tasks are
terminated before starting Virtual Dub or Scrabble.

Starting in safe mode is no real help in finding the problem, as I am
then unable to run the programs which suffer from the error while in
safe mode, and therefore am not able to re-create the circumstances
which create the error.

I'm running Windows 98 (not SE) on AMD 1.2GHz Duron, 512Mb (2 x 256
SDRAM 168pin, PC133), on mainboard Soltek SL-KAV, Chipset VIA Apollo
KT133A series (http://www.soltek.de). The most up-to-date bios and mobo
drivers are installed.

Cards inside include a Pinnacle Studio DC10+ motion jpeg capture board,
Creative Soundblaster Live, Adaptec SCSI card, 10/100 Ethernet, nVidia
GeForce4 video card.... all these cards were present in the system when
the machine was last working correctly, and so I would imagine they are
not causing the problem unless one of them has gone haywire.

Also a 2 hard drives on IDE1, a CD burner and a DVD burner on IDE2, and
1 SCSI hard drive on the SCSI card.

I'm not sure exactly when the problems started as there has been a lot
of changes in my system in the last few months, so I can't pinpoint when
the problems started to occur. The most recent changes have been BIOS
firmware updated, all CD & DVD drive replaced and firmware updated,
128Mb dimm removed and replaced with a 256Mb dimm, XP home installed as
a secondary OS (dual booting OS), ran Windows Update and installed all
critical updates/patches for both Win98 and XP, a dial-up modem removed
and replaced with Linksys ADSL gateway/router.

I'm yet to see this error pop up while the machine is booted into XP
Home mode.

What do I do next?
I can supply more info if required about any of my hardware/software
configurations.