Warnings in edmx file when upgrading from 3.5 to 4

I updated my solution from .NET 3.5 to 4.0, and thanks god, I just had to fix minor things. But what I don't understand is, the edmx file generated many warnings like this:

Error 2005: Mapping Association 'FK_CP_C' is redundant:
Its referential integrity constraint provides sufficient information.
You can safely delete the mapping information for this association.

Have you ever encountered this?

Should I do take the risk and delete the association开发者_JAVA百科s?

I tried to google it but wasn't able to find anything.

Thanks

Well FYI I made a backup of the project before, removed those associations thoat reported an error, updated the model, and the warnings are gone.

I missed to notice what kind of associations caused the warnings.

Hope this might help someone in the future.