[Haskell-cafe] How to check for memory leak.

I was using the code from http://www.haskell.org/hawiki/HaskellNewbie_2fTcpIpAndNetworking It seems to be losing a few Kbytes every call (i use 'top' on linux to check the RES field value). I dont know whether this is a memory leak or just the GC not collecting yet. I was just wondering What is the general method to check this. BTW, I have tried using -prof and -P, but not really able to see anything suspicious. Cheers, ed