[Haskell-beginners] ghci :load vs import

[Doug McIlroy]

I have module Powser stored in haskell/Powser.hs.
There is no file ./Powser*.

This loads the module
        shellprompt> ghci -ihaskell
        Prelude> :load Powser
But this can't find it
        shellprompt> ghci -ihaskell
        Prelude> import Powser

What might cause the difference?
(I am running ghci 7.8.4.)

Doug