"Simon Marlow"
If you could send us a smaller example that displays the problem, we'll be happy to look into it.
Well, here is a definitively smaller, although not too small example (182 lines total). Options are hardcoded in this version. Compile with ghc -o show --make Show2.hs -prof -auto-all and run as ./show +RTS -p to get the profile (also attached). Btw, I also get a warning before linking (only with 5.04-1 got from http://lambda.foldr.org/~michaelw/debian-unoff/ /dists/unstable/binary-i386/): /tmp/ghc16560.hc:1247: warning: initialization discards qualifiers from pointer target type I hope I didn't leave out anything. And if you have any comments regarding the code, I'd be glad to head them, too. Cheers: Feri.