Problem with APA 6th Ambiguous Citations

I’m using Win 7 with Endnote X7.3. I have a large document (>90,000 words with several hundred in-text citations and bibliography entries). I currently have APA 6th unambigous citations set to add a letter to entries with the same author and year. This appears to work fine, but the entries do not increment as you would expect, a, b, c, etc. Instead the entries in both the bibliography and in-text citations, for example, go from a to c even though there are only two ambigous entries. Or in another example there are three ambigous entries and endnote has them listed as a, m, and v. 

I’ve tried a few different “solutions” with no real effect.

  1. I tried switching to a different style and back

  2. I tried changing the style from add a letter to do not add a letter and back

  3. I’ve tried turning it on and off again

I’m sure endnote has some sort of counter where it tracks the ambiguous entry number, but I can’t find how to reset it. 

Any help would be appreciated!

See  a couple threads on this issue – but here is one: