demos and screenshots

So i’ve been very very bored and have played CoD 4 to alleviate the boredom… and i’ve become pretty good (or perhaps just lucky, your call) on single player… i’ve beat the post-credits airplane scene on veteran. Also I’ve beat the IW time for the training house at the start of the game, and I’ve tried to screenshot that and demo it for bragging rights (“demo or it didn’t happen”)… both of them haven’t worked – the screenshots are just vertical green lines of varying color, and the demos are apparently corrupted as the game crashes every time i try to play them back. this wasn’t a one-time phenomenon, any demos or screenshots I randomly take have the same results. has anyone else had these issues, and whether that’s a yes/no, which version of the game are you running? (if it has updated online or not is what i’m getting at…)