glad to see that i wasn't the only one who had this problem, lol.. it sux too as i had just packed mine, went to put the lid on and it went on cross threaded, and i couldn't get that sonbitch open for the life of me..
what i had to do was take it to work, and grind a flat spot on one side so that i could put the flat spot in a vice so that it wouldn't keep turning when i put the vice grips on it.. after i got it open, the mechanic at work told me to put a lil oil on the threads as its made of aluminum and aliminum is soft and can get screwed up easily.