Odd! Not only does it not have that behaviour in ghc-4.0[48], it also didn't seem to work when I tried coding it that way in C. Maybe tells you more about my C skills... ;-)

I'll wait until the stable ghc-5.02, and then try this again, just in case this has indeed changed significantly recently, rather than it just being me missing something obvious.

Indeed, it appears not to work in GHC 5.00.2, but I've checked that it does work with the forthcoming 5.02. Code is attached. Cheers, Simon