Bug? Unique class names...

Hi,
    I am trying to generate classes on the fly... as classes may get 
generated more
than once, I want guaranteed unique names (sounds like a job for newName)...
However, whilst the first example works, the second fails:

 >-- this works
 >test :: Q [Dec]
 >test = do
 >   k <- newName "k"
 >   c <- classD (cxt []) (mkName "MyClass") [k] [] []
 >   return [c]

 >-- this fails
 >test :: Q [Dec]
 >test = do
 >   n <- newName "MyClass"
 >   k <- newName "k"
 >   c <- classD (cxt []) n [k] [] []
 >   return [c]

In the second case this error is given:

    ghc-6.3: panic! (the `impossible' happened, GHC version 6.3):
            nameModule MyClass{tc a3dX}

Is this a bug? How easy is it to fix?

    Regards,
    Keean.