EPiServer CMS 5 R2 SP2

I thought it would be possible to save a pagereference to a custom pageprovider-page. I have a PropertyPageReference property and point out a custom pageprovider-page but I get a SQL exception. In the edit-gui it is ok, pagereference: "1111__XXXX", but when I save it throws an exception: The INSERT statement conflicted with the FOREIGN KEY constraint "FK_tblWorkProperty_tblPage". The conflict occurred in database "dbName", table "dbo.tblPage", column 'pkID'.

The pagereference is saved as an int in the database, so I cant se that the "RemoteSite" part of the pagereference is saved. So it tries to save my reference as "1111" and that page-id do not exist, except in my pageprovider.

Have I missed something? Should it be possible to use PropertyPageReference to set a link to a custom pageprovider-page?

/Hans