The +RTS options don't seem to be working for me on Linux (Redhat 7.2, ghc 5.04 and 5.04.1 installed via the .rpms).

One of my programs will happily consume all available memory, even though I have +RTS -M64M, and another program fails with

Stack space overflow: current size 1048576 bytes. Use `+RTS -Ksize' to increase it.

even though I'm using +RTS -K10M.

Well, it works here... if you say "+RTS -?" does it print the help text? Could you post the exact command lines you're using to compile/link the program, and the command line used to run it? Cheers, Simon