panic! (the `impossible' happened, GHC version 5.04.2)

Compiling LinOpt           ( Linear_opt.hs, interpreted )
ghc-5.04.2: panic! (the `impossible' happened, GHC version 5.04.2):
        nameModule a{-roJC-}

Please report it as a compiler bug to
glasgow-haskell-bugs@xxxxxxxxxxx,

My module contains newly the deriving clause - well it was an experiment:

newtype Matrix a i e = Matrix (a i (a i e))$
        deriving (IArray a e)$

Sincerly,
-- 
Stefan