Implicit parameters cause strange behavi

[nobody]

ghc-5.00.1 (with glasgow-exts) compiles the following
program:

> foo :: ((?x :: Int) => b) -> Int -> b
> foo s z = s with ?x = z
> main = foo (print ?x) 42

Running the generated code prints nothing. (No output
is produced
even if we add putStr "Hello world\n" before the call
to foo).

[simonpj]

Logged In: YES 
user_id=50165

Works fine with GHC 5.02 (about to be released)