I had the same problem with the IF#2 from the first time I tried it. When I stirred it there were little balls that didn't assimilate into the liquid so I started using my shaker container that has a locking lid and no more problems like that. It mixes perfectly every time.
I keep my IF#2 stored in a glass canning jar with the lid very tight so I wouldn't (for me) be hesitant to use it if it were several months old but I would not use it if it had been stored in the baggie it came in after that long. Powdered herbs don't have a long shelf life.