newtype Floating a => Vector a = Vector [a]

Okay, I now know a little more about this, with help from friends. The obvious Functor instance seems not to work with GHC 6.2.2 but does work with GHC 6.4. With 6.2.2 I can still use GHC's newtype-deriving extension to derive an instance for Functor, I'm just not sure how I can get an explicit instance past 6.2.2 without it complaining about my syntax or not being able to deduce Floating a or b. This isn't a show stopper, I'm just intrigued. -- Mark