Broken Cabal

Hello,
I am not sure if this is the correct place to report this problem, but
there is a bug in the Cabal distributed with GHC.  I used the simplest
possible Setup.hs file as shown in the documentation.
All the modules in my library are in a directory Monad, e.g.
Monad/State.hs, Monad/Reader.hs, etc.

When I type:
> runhaskell Setup.lhs sdist

I get a source tar-ball but when I extract the files I get the following:
monadLib-1.2.2/
monadLib-1.2.2/nad/
monadLib-1.2.2/nad/BackT.hs
monadLib-1.2.2/nad/ExceptT.hs
monadLib-1.2.2/nad/Reader.hs

Notice that the "Mo" part of the directory name is missing.
-Iavor