I've built a program with the -threaded option using ghc. This option is supposed to link your program to the threaded runtime with support for multicore CPUS (mine is a dual core). The program pukes with the message in the subject line when I try to use the -N option to tell it to use both CPUs. I'm reasonably sure that I actually have the threaded runtime because initially I got a runtime message from the program about how GTK is single threaded and can only be used with the threaded runtime using runtimeunsafeInitGUIForThreadedRTS instead of the standard initGUI. I made the change in the code and now the program runs but still does not know the -N RTS option. This problem seems to affect all my programs. It is as if the threaded runtime is there but doesn't know any of its special flags. This is the line I'm compiling the program with. It's a life game clone in case you're curious. Compiler is ghc-6.4.2 on 64 bit AMD dual core running Gentoo Linux. - Greg ghc -threaded -package gtk -package glade -o hlife hlgtk.o Hlife.o ____________________________________________________________________________________ Check out the hottest 2008 models today at Yahoo! Autos. http://autos.yahoo.com/new_cars.html