GA-8KNXP and Windows 98se

I have set up a GA-8KNXP Rev. 2 motherboard-based system (FG BIOS) to
dual boot to Windows 98se (IDE 0) and to Windows XP Pro (SATA HD,
Silicon Image controller). The system will boot fine to either OS with
only one of my 512 RAM modules (Kingston KVR400X64C3AK2/512 400MHz DDR
PC3200 DIMM 3-3-3) at pos 1 but not to Windows 98 with two modules pos1
and pos4 in place; it will only boot to WXP with the two modules
installed. With the 1024 GB of memory installed, W98 starts to load but
gets lost after showing the desktop and never finishes.

I have learned about the memory issues with Win98 and have altered the
system.in file with statements in the [vcache] and [386enh] sections to
limit cache and total memory but these have not helped with the problem.

I am wondering if the issue might be motherboard related as well since I
have an ASUS P4PE motherboard system with 1 GB of RAM which boots to
Win98se and W2000Pro SP4 with no problems. In fact, I made no
modifications to memory usage in Win98se and did not even know about the
RAM issues until I got the Gigabyte motherboard.

I would appreciate any suggestions.

Steve