Trouble with GHCi and HOpenGL

Hi! I've installed HOpenGL (using cygwin and windows 2000). But when I
try to run ghci with HOpenGL I just get these error messages:

>ghci -package HOpenGL
   ___         ___ _
  / _ \ /\  /\/ __(_)
 / /_\// /_/ / /  | |      GHC Interactive, version 5.04, for Haskell
98.
/ /_\\/ __  / /___| |      http://www.haskell.org/ghc/
\____/\/ /_/\____/|_|      Type :? for help.

Loading package base ... linking ... done.
Loading package haskell98 ... linking ... done.
Loading package lang ... linking ... done.
Loading package HOpenGL ... C:\Program\Haskell\ghc-5.04\bin\ghc.exe:
can't load
.so/.DLL for: HOpenGL (addDLL: unknown error)


What does this mean? When I run ">ghc an_HOpenGl_program.hs -package
HOpenGL" everything works and I can run the compiled program, but why
doesn't ghci work ? Can it have someghing to do with this error
message I got when I built HOpenGL:

...
package=HOpenGL || true ; \
   "/cygdrive/c/Program/Haskell/ghc-5.04/bin/ghc-pkg" --config-file=""
--force - -add-package < HOpenGL.conf ; \
fi
package `HOpenGL' not installed               <--- Why ?
Reading package info from stdin... done.
Expanding embedded variables...done.
warning: can't find GHCi lib `HOpenGL.o'      <--- Why, again??


Does anyone know how to get ghci working with HOpenGL? Sorry if this
question is stupid - I'm a student and am learning Haskell right
now...