Problems with EDM associations

Question

Hi,

I'm making an OData service and using an EDM to map the structure of my database and specify associations between tables and create Navigation Properties.

I've imported my tables into the EDM using the wizard. Things compile fine until I put in associations. I'm sure I've been able to do this before but for some reason it is screwing up.

I have a table Attribute

AttributeId     int   PK
AttributeName   varchar(100)

and

AttributeItem
AttributeItemId       int PK
AttributeID           int
AttrributeItemValue   varchar(100)

I want to link AttributeId between the two tables with a 0..1 to * relationship (from Attribute to AttributeItem).

I'm constantly getting problems. initially this error:

Error 3027: No mapping specified for the following EntitySet/AssociationSet - AttibuteAttributeItem

Then once I've fiddled with the mapping details of the association I get this error:

Error 3024: Problem in mapping fragments starting at line 91: Must specify mapping for all key properties (AttributeItemId, AttributeId) of End AttributeItem in Relationship AttributeAttributeItem.

I've no idea why it's doing this.

Any idea what I'm missing?

thanks,

B