Haddock can't parse data declaration involving operator

[Stefan Reich]

Hi,

I hope this is the right place to ask about Haddock problems?

I'm using Haddock 0.6 (RedHat RPM module) under RedHat 9. When I invoke 
haddock on this file (Op.hs):

	module Op where

	infixl 4 :=
	data a := b = a := b

I get the error "Op.hs:Illegal data/newtype declaration".

Is this a known problem?

Asking more broadly - maybe there is another tool that does what I need: 
I just want an overview of all my modules including their exported 
identifiers and all type signatures (including inferred signatures).

Thanks in advance,
-Stefan