trying to get hat-make to swallow my code

Hello,
    I've written a haskell program which is not behaving quite as I'd 
expect.  Up till now, I've used Debug.Trace to understand it, but this has 
become a major pain, and I was hoping to use hat.

When I run hat-make on the code, I get thousands of warnings followed by 
the following errors:

./Hat/EHM2Alt.hs:316:32: Not in scope: `Hat.Ix.grange'

./Hat/EHM2Alt.hs:331:29: Not in scope: `Hat.Ix.gindex'

./Hat/EHM2Alt.hs:342:29: Not in scope: `Hat.Ix.ginRange'

Is this enough of a clue to track down what is happening?  I'm not sure 
what other
information would be relevant.  I'm using GHC on Windows.  One of my 
modules imports Ix, and several of them import Array.

Any help would be greatly appreciated.  Thanks.

Tom.