I get to a point in Contact Checkpoint 5 and can't get past it... I've tried many\many times no luck... I've tried m any different ways to destroy the anti-aircraft guns with no luck... Is there any trick to doing it??? Is there a cheat that might help???

wasn't that the mission where you need a zues? or was it you'll have to pinpoint them for airstrikes, sorry can't remember

Please refresh my memory. Is 'Contact' the first mission in graw1? (I didn't play that for a while). Where's that AA and where are you (situation)?
You don't need cheats.