I have a similar problem--IE will tell me it's low on memory and that I have to close some windows when I only have 2 or 3 open! And I have 32 MB RAM allocated to it (my total physical RAM is 128 MB).
It seems to be a temporary problem, though--
if I quit IE and then launch it again, I can have 10 windows open without out-of-memory messages...
I guess I just have to think to myself, "welcome to the world of M$ software"...
the first piece of it that I use on a regular basis...