So I know that it's almost never the insulin that's the problem--but is there any value in trying a different cartridge? The switch to this one was around the same time that Leda started going higher (though I can see it potentially starting before the switch), and it was the cartridge closest to the back of the fridge making it remotely possible that it froze. I have 4 more insulin cartridges from the package, so maybe I'll try a day or two of a different cartridge--it can't hurt, eh?