With ghc-5.00.1, the compiled Foo.a, Foo.o are each of 7Mb, ghci -package foo ... Prelude> :l T_ loads the interpreted demo examples (importing Foo.o), and this needs more than 45Mb heap.

As we've mentioned before, GHCi has some memory leaks. This is on the list of things to investigate, but we haven't got around to it yet. Cheers, Simon