Socket module does not export Socket (datatype) !

[Ian Jackson]

I'm writing a program which does
 import Socket
but not
 import SocketPrim

GHC complains that the type constructor Socket isn't in scope.
Indeed, in Socket.lhs from GHC 4.04.19990916 I see that Socket isn't
exported, even though a function listenOn :: PortID -> IO Socket is.

When I say
 import SocketPrim (Socket)
all is well.

Thanks,
Ian.