I found this page that may help.

Here is a link that might be useful: Scott

I would first make sure the tire pressure is the same front to back. back usually runs between 8 to 10 depending on how much cushion you like and the front 10 to 12 depending on how easy steering you like. Set it on level concrete and use measuring tape. Some manufactures have the front of the deck lower than the back Usually about 3/4" lower in the front, not owning your model can't say if your model requires this (probably not out, unless you been tampering with it or something worked loose?), side to side should be the same and mostly it would be the one off. Usually your blades being dull or worn out cause and uneven cut. I would take a close look at the blades also.