|We used to call it "printer creep" as the labels creep down the label till they were printing in the space between lables.|
I could never find a universal fix, but you might try updated print drivers as well as playing with the pitch and column lengths.
It was always a hit or miss kind of thing. Each printer and each label had their own different fix.
I take it your using Avery labels.
You might want to check the Avery site, they may have more info.