Illegal operation with Win 98se

any ideas on this? works fine in xp, but the same usb flash drive in a 98se box brings up the followin error on load.

THUNDERBIRD caused an invalid page fault in
module THUNDERBIRD.EXE at 017f:00828e83.
Registers:
EAX=00000000 CS=017f EIP=00828e83 EFLGS=00010286
EBX=6031d23a SS=0187 ESP=00dbf068 EBP=00dbf0f4
ECX=0283d8a0 DS=0187 ESI=00000000 FS=b5c7
EDX=00dbf0cc ES=0187 EDI=00dbf2c0 GS=0000
Bytes at CS:EIP:
8b 08 50 ff 51 14 a1 a4 1e 99 00 6a 03 56 8d 4d
Stack dump:
00dbf0cc 0242d040 00a4fb00 00ef0a50 00000008 00dbf098 6009aff4 6031ffe0 00ae23cc 00000000 00dbf0f0 02417050 00dbf0d4 6008802d 01be75e0 13842f9a