[Haskell-cafe] Trouble using HDBC-postgres on Windows - can't find libpq.dll

I've compiled HDBC 1.0.1 and HDBC-postgresql-1.0.1 under Windows with a little tweaking. However, when I try to run the tests I get this error:

runghc -package HDBC-postgresql runtests.hs ghc.exe: can't load .so/.DLL for: pq (addDLL: unknown error)

libpq.dll is in my path, and I added the correct paths to the .cabal file when I built it. Does anyone have an idea what might be the problem? Justin p.s. I have postgres 8.2 installed if that matters.