The only thing I can think of is that maybe the glycin had oxidized too much. How old is the mixture and how old is the glycin you mixed the formula with? You probably know that fresh glycin is almost white, but that it darkens steadily as it ages.(posted 8546 days ago)I should think that the use of metaborate instead of carbonate would have reduced the activity rather than increased it, but it would have held the pH steady throughout, whereas with the carbonate it would have dwindled over time--this might have given more activity over the long run.