I keep hearing and reading about the importance of making sure all the unused inputs are pulled low with a resistor. No reason is given other than "don't keep them floating because you'll get unpredictable results!"
If you take a look at the picaxe 28X board, you see that all the digital inputs are pulled low with a 10K resistor. I understand that this makes it easier to just connect a switch to the pins on the board without having to add an external resistor. The analog inputs are left floating, almost as if by design.