Gotta go with Grub on this one. Sounds like you got some moisture and it wasted the powder. There was a guy who told about buying like 200 worth of powder and he left it in his car in bright sunlight and windows closed.

He tried everything we gave him him to try and it still didn't matter he tossed it bought more and no more problems.

Get ya some new stuff and when you store it make sure it's in a cool dry place.

Fatman