Yeah, I'm not at all sure what the cause is, but I've worked around it with HIMEMX. So far so good.

I've been prepping install images of PC-DOS 7.1 and MS-DOS 98. I'm going to add FreeDOS 1.1 and OpenDOS 7.01 WIP before I'm done. My goal is to evaluate resource consumption and compatibility across a panel of software using the different available kernels, memory managers, and mouse drivers.

Does anyone have any software examples they'd like to see tossed into the milieu?

Software I'd Like to Get to:
Monkey Island
Monkey Island 2
Privateer
X-Wing
Tie Fighter
Allegiance
Jagged Alliance
AutoCAD R14
QFG Series Including 4 1/2
Ultima Series

DOS 7.1 from Windows 98SE is my DOS of choice. Clearly superior to 6.22 with FAT32 support (which means bigger partitions and more free space on small ones). I didn't have any memory problems, of course some config.sys tweaking is needed. With MEMMAKER you can get a bit more, and with QEMM even more.

On the other hand, MS-DOS 8.0 from Windows Millennium really sucks, even after patching to make it Windows-independent. And I actually did encounter some utility (LFN driver I think) that refused to run due to version checking done wrong (claiming that DOS 7.x is required).