The only other thing I can think of is to re-check your table_a to table_b and table_b to table_c relationships. If you accidently went from c to b instead of b to c then b will have two incoming relationships which is a no-no.
>Having another relationship in the code would require an explicit call to "set relationship to" wouldn't it? If that's correct, I can see no other relationships for these tables. This form has a private data session, that should mean that a relationship set elsewhere would not be valid here. Is that correct? I will look further but let me know if there's some other syntax I should check for.
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>Thanks!