Broken Screw
Try the spring loaded automatic center punch first before you drill it. You may be surprised. I've actually removed many broken bolts this way. You just use the center punch on the bolt in a counter-clockwise fashion, and (hopefully) the springing action of the punch will bust it free. Worth a shot anyways!
If you don't know what it is or have never seen one, you should be able to pick one up at your local hardware store for under $7. Everyone should have one of these babys in their toolbox.
http://generaltools.com/product.asp?action=prdupc&prid=358§ionid=4
Try the spring loaded automatic center punch first before you drill it. You may be surprised. I've actually removed many broken bolts this way. You just use the center punch on the bolt in a counter-clockwise fashion, and (hopefully) the springing action of the punch will bust it free. Worth a shot anyways!
If you don't know what it is or have never seen one, you should be able to pick one up at your local hardware store for under $7. Everyone should have one of these babys in their toolbox.
http://generaltools.com/product.asp?action=prdupc&prid=358§ionid=4