The Ie5 package doesn't only provide Ie5. There are several core fixes in it. I promise you that installing Ie5 fixes at least one memory bug.
When I went from 64 to 576 Mo of ram, I dsidn't notice a thing, cos I had already Ie5.
After a while I had to format and reinstall windows (98 fe).
On the nude install, it was hardly possible to launch a program. Win thought I had too few memory. Then I installed Ie5 (no other patch), and the mem problem was gone.
I've reproduced the problem several times with the next clean installs I did after.