Ticket 1031 workaround?

[Adrian Hey]

Hello folks,

I seem to have hit this problem..

  http://hackage.haskell.org/trac/ghc/ticket/1031

(I think, at least I'm getting a very similar incomprehensible
error message :-)

I tried using bang patterns instead of `seq` like this:

 > let a0_ = f a0 a in a0_ `seq` (# l,hl,a0_,r,hr #)

becomes ..

 > let !a0_ = f a0 a in (# l,hl,a0_,r,hr #)

but I still get the same error.

Could someone who knows explain exactly what the problem
is and what the workaround is (if there is one)?

Thanks
--
Adrian Hey