bad cartridge or am I overlooking something?

This is a question for some of the serious analog battle axes in the community. I recently decided in the past year to dive into analog. I had been using a planar 25 for about 8 years and found a beautiful VPI HW19MKII in mint condition for an acceptable price and made up my mind. In January of this year I purchased a benz mc20e2lo mc cartridge that I have always seemed to have trouble setting up on my planar 25. Since installing this cartridge on my rewired rb600 and mounting it at exactly 222mm from the spindle on my armboard and aligning it using the baerwald points on the VPI I have noticed several things going on that are not right. The tracking force benz suggests is 2g, when I set the force at 2g and adjust the antiskate the left channel output is noticably higher. above approximately 2.15g the right channel does the same thing. If I get the weight just right sometimes it favors the left, sometimes the right and sometimes it sounds ok. The table is level, the arm is level with the platter and this is the only source I am having problems with. Does anybody know what this could be other than a defective cartridge? The cartridge is still under the 2 year warranty and I would like to take it back to the dealer, but I would like to be informed of what to expect so that I don't get railroaded. Any information or suggestions would be greatly appreciated.