I know it was definately not soggy. I only water my pothos sparingly and the pot it was in had good drainage. When I pulled it out of the pot, it was dry all the way through. I think the white stuff was some kind of mold. At least that's what it looked like, and whatever it was it was killing the
plant. I think the only reason that it grew a mushroom (which was over a year again and never returned) must have been that some spores got in there somehow.
My other pothos, which I've only had for 7 or 8 months, are doing great and I only water them once or twice a month. I know that I can start a new
plant from the cuttings, and I'll make sure to sanitize the pot really well. I love that pot and don't want to give it up.