I was very surprised when I discovered (writing a bit more complicated program) that a program like

...

import Numeric ( floatToDigits ) print $ showFFloat Nothing 0.01 ""

enters in to infinite loop. I found that (formatRealFloat FFFixed Nothing) do not like displaying numbers less than 0.1.

Yes, the code was recently discovered to be buggy and has been fixed in the revised Haskell 98 report. GHC 5.02 is using the fixed version. Cheers, Simon