Question about Resistance 2 Controls

[Flashbaak]

I've discovered that while I'm playing if I push forward to move, my character inexplicably begins turning toward the left. Sometimes it appears to be worse than others, and I can't figure out why (occasionally it isn't happening at all). I did a google search and it doesn't seem that this could be caused by the sixaxis tilt functionality.

It can actually be fairly frustrating, as you must constantly be correcting to the right while moving to actually run in a straight line.

I've checked to ensure that when the game loads, the analog sticks are not pressed. and the character isn't moving constantly even when I'm not pressing on the analog sticks.

I'm fairly new to FPS. Resistance 1 was the first one I enjoyed enough to actually play all the way through...so I'm not sure if there's something I'm missing about how these things work.

Anybody have any ideas?