Error importing Control.Monad (liftM2) with newtype

This happens with both nhc98 1.16 and 1.18:

$ cat Q.hs
module Q () where
import Control.Monad (liftM2)
newtype A a = A a

$ nhc98 -c Q.hs
nhc98comp: isRealData InfoClass 1 Prelude.Monad IEnone \/ b . (1 b) [38,39,40,41] [] [(5,([],[])),(25,([],[])),(26,([],[]))]


Thanks
Ian