I know this was mentioned before, but are you absolutely sure the floor is level and the cabinet is not in a twist? That little bow in the wood shouldn't cause this kind of issue, and I know from experience putting a cabinet in an uneven floor will cause all kinds of fit issues that you wouldn't expect. Cabinets will flex some...no matter what corner protectors you have in place. Just make sure you aren't trying to fix something that isn't necessarily broken. The easy way to tell is to move the machine to a different part of the floor to see if the gap changes.