Closing The Loop
Originally Posted by dbuchheit
I want to thank everyone for their responses and close the loop on this question.
I did contact Sherry at PF and she was very courteous and helpful. She concurred that it could be temperature dependent and suggested that I try storing the mixture in a warmer area.
I reheated and remixed the existing batch and have stored it at room temperature (upstairs) and this time the borax stayed in solution.
Coincidently I ran into a chemist friend yesterday and he confirmed that solubility is absolutely temperature dependent.
So thanks again and I'd say case closed.