So if I understand correctly, everything you are referring to is in direct relation to the melodic minor scale.
I'm not sure I would call it a problem in it self, but In C melodic minor (
sorry Terry Riley ) The segment B C D Eb create a diminished fourth/major 3rd. Then when you apply this concept to any chord you end up with a diminished fourth...
C E G could be C Fb G if it comes from C Db Eb Fb and it's from the Db melodic minor scale.
C Eb G could be C Eb Abb because Eb Fb Gb Abb from Fb melodic minor.
This is what I understood from your other thread. I am not saying I agree with this but this is what I think you mean.