Had the same problem with a VX-II, wouldn't adjust unless I popped it a few times. Really got to were I don't care for leupold much, I hate the windage adjustable bases too. Seen a lot of broken screws on them.
I pretty well stick with dual dove tail bases and vortex optics. The viper line compares well with the VX-III and a lot less money. Always plenty of adjustment too. I still tap the scope when I'm done, but it always returns to zero very well.