I don't see any reason for Repositary pattern to NOT work with Entity Framework. Repository pattern is an abstraction layer you put on your data access layer. Your data access layer can be anything from pure ADO.NET stored procs to Entity Framework or an XML file.
In large systems, where you have data coming from different sources (database/ XML /Web service), It is good to have an abstraction layer. Repositary pattern works well in this scenario. I do not believe Entity framework is enough abstractive to hide what is going behind the scene.
I have used Repositary pattern with Entity framework as my data access layer method and is yet to face a problem.