It confused me at first, too. I couldn't get why the stripper we bought for our deck project (and which came highly recommended) wasn't doing the job. Maybe the previous owners laid on some crazy E-6000 version of exterior/deck paint??? Or maybe not, since it was chipping pretty badly and had seen better days.
After reading several reviews and hearing personal recommendations, we decided to give Behr Premium Wood Stain & Finish Stripper a try. It's supposed to be able to take anything (latex or oil based) off of wood surfaces. And at only $19 for a gallon of the stuff, we figured we'd go for it.
After rinsing (and rinsing and rinsing) the stripper off of the deck, we decided on renting a heavy duty drum sander.
We decided on Deckover for our application, and the texture and finish has turned out great, and we LOVE the color!
UPDATE: The deck is now completely finished! Yea!