It's on the PS2, and I haven't used a single cheat. I hate using them they ruin the game.
Actually technically I haven't used a cheat and then saved the game, whenever I've tried one out for a laugh I always turn off the console or restart from the last save point.
It's not a controller issue, all my other games play fine, it's a built in glitch I'm sure of it, it's like he's frustrated or bored or something.
It's got gradually worse, and perhaps if he was only jumping off bikes or out of planes and cars I'd be thinking my triangle button was busted but while driving along the camera will switch to look left or right and Carl will fire out the window, if my buttons are busted it means my L2 and R2 and circle and triangle button are all busted.
It started at the Verdant airstrip, I consistently saved my game there because I always loved jumping in a plane. I'm thinking maybe it's the games way of getting you to move on and do something else, it's totally bizarre I've searched the net and can't find any other record of it happening.
Thanks for your input guys, I'll try swapping the controllers over but I'm positive it's a built in thing because I've done something within the game.
Edit: I did murder my first girlfriend, do you think that's it? She was always moaning and ringing me up so I battered her with a baseball bat thinking she'd be magically OK again but her heart never reappeared on the map, it wasn't long after that it started happening, maybe she was cursed?
Edit 2: ...and who says this game causes violent behavior!