How do I keep the rice cooker from boiling over? I am having epic rice-cooker failure here.

I measure out the amount of rice suggested by the little cup thingy. I rinse it with a bowl and a strainer until the water is clear while rinsing. Then I put the rice in and fill it to the appropriate line in my Rice Cooker with fresh water. After cooking for a little while, it immediately begins to boil over and nasty bubbles start popping out of the little hole in the top, dumping yucky, sticky water all over the place.

The Rice, when all is said and done, is alright but it's a hell of a mess! What am I doing wrong?
I've heard that adding a little olive oil (any kind) can help with bubbling over.

Otherwise if you don't get any answers, consider that your rice cooker might be broken. If you get that far, try to borrow someone else's and repeat your method.