You need to put your water supply into numbers, so you can rule out a mismatch with an indexing valve. "Seems to have good pressure" is not really useful as data.
Have you opened up the non-working valve and made sure it was not jammed, and that everything moved freely?
This post has been edited 1 times, last edit by "Wet_Boots" (Mar 18th 2013, 2:31pm)