Greetings,(posted 8531 days ago)I use XTOL quite a bit, but only in the 5L sizes. The problems that I've heard always related to the 1L sizes and was a packaging problem.
Once mixed, I store it in used soda pop bottles for more than 9 months with all air remover. (If you use these, be sure to use the plastic bottles intended for carbonated beverages, as they have a laminated vapor barrier.) The negs developed in fresh vs. 9 month old XTOL had identical density readings.
Regards,