Why aren't my boms updating quatities?

Hello;

     Just wondering why when I add a nut in an assembly, and my quantity 2 becomes 3, the bom still says 2?

I have automatic update checked in the Tables/Boms/ settings. If I insert a new bom it is quantity 3, but I don't think

I should have to insert a new bom just for adding a nut. 

Thanks in advance for any input;

Rob_D SW2014 Sp4

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