You might want to switch your shoes. I've discovered some shoes are better than others for exercising on machines. I've had various shoes that will make my feet numb (pressing on a specific point?) while others wouldn't. You can also try moving your feet around a bit while you are on it.
Hey all...just wanted to let you know that today I tried stretching my legs out completely before starting on the elliptical. Although the numbness didn't go away completely, it wasn't as bad as usual, and it seemed to prolong it until I had been on for 30 minutes.
That happens to me too. I think it does have something to do with putting more pressure on the ball of the foot instead of all across the foot. I'll have to try that myself...