Hi there again.... I believe this is quite important for the Topic, so I'll add it:
Maybe I'm doing something wrong....
In a Grid woth a foireign key column, if it's value is null, it doesn't work. You can click on it and choose a value from the dropdown, but after clicking it becomes null again, and if you try to "Save Changes" it sends the Null value to the Database.
Image attached.
Any ideas about how to solve this problem?