Label data moves within margins

[KaraW]

I'm printing labels that vary in number of lines. Some have four, some five,
but all data fits in the parameter. It seems that the "larger" ones push
down the one directly below, ultimately causing the data to bleed over. I am
using Avery 5160 size. Has anyone else had this problem? Is there a way to
make the data static so that the spacing can't fluctuate? Any help is MUCH
appreciated.

Thanks,
Kara