Problem with using BNF converter tool

[robin abraham]

Hi all,

I am sending this here and not to the bugs list under the assumption that I am 
doing something wrong...

I am trying to use the BNF converter tool. When I try it on simple examples, the 
first step (generation of the .y and .x files) goes through. When I run happy on 
the generated .y file, I get the following error:

happy.bin: internal error: stg_ap_pp_ret
    Please report this as a bug to glasgow-haskell-bugs at haskell.org,
    or http://www.sourceforge.net/projects/ghc/

Any help/guidance would be very appreciated.

Thanks
Robin.