There are two nuts, 1/2" I think. Right front and left rear, I think. (I removed mine about 2 months ago and I can't believe I don't remember it more vividly. I do still have the old toilet sitting out there so if you still have trouble with it, I'll check it more closely and get back to you.)
IMO, your water troubles are probably from the toilet. That seems to be where mine came from.
If you look at my pictures, you will see a picture of my tub in partial disassembly. PizzaChop Pictures - Tub Removal
Browse through them as I'm sure they'll be informative (maybe too much so)