not cutting the entire area evenly

I am consistently having problems with my handibot not cutting at the same depth across the plane of the material. Even on corion which can't be too 'off'. I have pocketed and still have the same trouble. Had to cut @ .34 to get a .23 piece cut through and then some of it didn't cut. Worse on the upper right hand side. Any ideas of what I'm doing wrong? I zero xy at the beginning and zero z ON the material and it still doesn't cut deep enough...help:-)

As Mark mentioned in the other thread this could be caused by binding. We've created a troubleshooting guide for that here: [shopbot.dozuki.com]
Other things to think about though; is there any debris under the handibot which could be causing it to not sit flat on your work surface? How close is the tool getting to the bottom of its Z-travel during these cuts--it could be that the tool is "bottoming out" during some part of the cut and losing z position. This could be fixed by loosening the router bracket to drop the router or by dropping the bit a little lower in the collet.
One thing that I always do when I'm working on a detailed carving is to zero the z axis directly over the part of the material where I will be making the most shallow cuts. This helps ensure that the z-zero is accurate where it matters most.
I'm sorry that its been tough getting your cuts to work so far. If these suggestions don't work out be sure to call into shopbot and we will get everything straightened out for you!