From what I heard, they got the rights to I, Robot, grabbed some script about a robot uprising that they already had optioned, and slapped a few things on it.

This is apparently fairly common. If there's a Hollywood movie based on something that doesn't really align with the original, there's a good chance that this is what happened. Starship Troopers was the same way (though that's a whole different ballgame on whether the Hollywood version is good on its own merits).