[Template-haskell] Type variables within type quasiquotes

Hi, Contrary to what's stated in GHC's 6.6 user's guide (http://www.haskell.org/ghc/docs/6.6/html/users_guide/template-haskell.html ) type quasiquotes seem to work just fine when type variables are not used (i.e. things such as [t| Bool |]). But unfortunately GHC complains when I make use of type variables [t| Maybe a |] leads to "Not in scope: type variable `a' " Am I doing something wrong or did I run into one of the reasons why the guide says that type quasi-quotes are not implemented? Thanks in advance, Alfonso Acosta