Is this the map that comes with a novell client?
I've run across similar problems when running DOS programs under 98. Especially if said DOS program was not careful with it's memory management. One of the programs is not playing nice. It could also be that the DOS program is wanting more of a footprint than the shell is willing to hand out after allocating for Perl. Are you running the most current Active State build? Without knowing more of your problem, I'm afraid conjecture is the only help you'll recieve at this time.

And just for the record, I'm running 98SE and haven't run across any memory problems, but I haven't done many shell calls either.