Unresolved RAMPS 1.4 problems in R1 beta

Hey guys, Im hoping that perhaps one of you gurus will be able to help out with a RAMPS 1.4 problem. My old ROBO R1 beta has been chugging away for the past couple of years but the board finally faded away. I bought a new Arduino/RAMPS and have gotten most everything working again with 2 exceptions: 1) When I hit "home all" my bed only moves a bit less than 10mm before stopping. When I hit an individual home command, it works properly. When I move it separate from the home command, it works perfectly. My drivers are working and properly adjusted (yes, I've tried higher voltages without any noticeable differences). Jumpers are consistent with all the others. Thoughts? 2) Perhaps a worse problem is this: The typical z-steppers on this setup are run through pololu driver for two motors. No matter what I tried, this didn't work with the new board. I read of others having a similar problem and utilizing the unused 2nd extruder spot for running the two z-steppers independently. Marlin has a provision for this in "adv.h" I uncommented the proper line and lo, both motors work great except one is faster than the other. After about 10 mm of travel, the z starts becoming tilted until one side is no longer engaging the nut on the lead screw. My theory is that the 2nd extruder driver is running at the extruder steps per mm which is c considerably different from the z steps per mm. Having tried all sorts of different combinations, pololu voltages, etc. I can't think of anything else but am open to ideas. If it is as I suspect, is there a way to match steps per mm in the movement definitions of the Arduino sketch? Could the new RAMPS shield be defective? I know it is a lot and maybe no one is familiar with what I'm asking, but I appreciate your efforts if this is something you might have some ideas about.