G!Accuracy is causing slide holes NOT to drill. What up with that???

By default the G!Accuracy is set to =UCN(5,2)   5 places for inch and 2 places for metric

So we processed cabinets and NOT drilling on the RIGHT side for a certain slide. Changed the slide to same mfg but different model and some work fine. Then all of sudden one model omits the LEFT side drilling but drills the RIGHT side? 

Changed the G!Accuracy to 4 places vs 5 places and it works as it should drilling on both side for all of them.

 

So what is the issue ... just a rounding snfu? Why this specific slide, with a certain side material thickness, just the RIGHT side on one slide and LEFT side on another.

How could being "more" accurate cause this issue??? Anyone have this happen before??