Surprised I haven't seen this, but have you tried a different cable? Display port? Could be worth a shot.

I usually can't even tell the difference between 30 and 60; anything more is a waste.

Depends on the game as to whether it will be noticeable. If you aren't looking quickly in multiple directions like in a first person shooter then it is not nearly as noticeable as a slow scan at 60 generally looks pretty good.

It also matters how well your video card matches up to the monitor refresh rate because otherwise you might end up with a frame being displayed twice.