NOD32 caused an invalid page fault

When running nod32.exe, this illegal operation error displays on exit:

NOD32 caused an invalid page fault in
module KERNEL32.DLL at 018f:bff9dfff.
Registers:
EAX=006cfe38 CS=018f EIP=bff9dfff EFLGS=00000246
EBX=81db8090 SS=0197 ESP=006cfc88 EBP=006cfe38
ECX=00000197 DS=0197 ESI=00030604 FS=501f
EDX=006cfe28 ES=0197 EDI=00000000 GS=0000
Bytes at CS:EIP:
cc a1 e0 9c fc bf 8b 00 66 64 f7 05 1c 00 00 00
Stack dump:
10000000 81db80d4 81db913c 81db7f10 00000545 cb2298f0 bff7b9c5 006cfce4 00000048 81db1cbc 00000024 bff7a3a0 81d51000 81db1ce0 00000048 00000000

The problem only occurs if I open nod32.exe and exit without performing any action. If I run an on-demand scan, the exit is clean (no illegal operation). Also, if I go to Setup and hit Save Configuration, even though no changes are made the exit is clean. If click on Help, then close Help the exit is clean. I also tested the occurrance of this error after killing every process except Systray and Explorer. I do not have NOD32 set as active at all times nor am am I using it to scan e-mail - it is being used as an on-demand scanner only, but I have tried every other configuration possible and the problem still occurs if I exit without performing any action.

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NOD32 system information
Version: 1.337 (20021217) Eval
Installed on: 12/24/2002
Virus database build: 2688
Environment version: 1.047
Last Update attempt: 12/24/02 21:17:25

Operating system information
Platform: Windows 98
Version: 4.10.2222 A
Common controls version: 5.81.4916
RAM: 511 MB

Diagnostics information
Base module build: 2688
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Has this happened to anyone else, and does anyone know what is causing the problem?

Your help is appreciated,
CatThief

Update: Problem solved! It turned out to be a conflict with a process I missed killing when going down the list - File-Ex (version 2.12d). Thank you Paul!