Let's Make Robots!

Analog pins not working

Hi all, I switched over to arduino from picaxe and was hooking up a few sharp sensors when I realized only some of my pins worked. Three of them (ao, a1, and a5) give me constant values regardless of what is hooked up to it and the other three work perfectly. The board is an uno r3 and the sharps are the long range variety. Any help would be appreciated.