Sometimes I get a similar issue when I kick out W2s and 1099s at the end of the year. I was surprised to find that my problem was related to slack in the printer itself - tried a different printer and the problem went away.
Maybe next try a different printer, if the problem is the same, then it is the report... Or try re-starting the print job from a different page and see if the drift is consistent - maybe you can see that a record or series of records is returning more or less data and changing the following areas to be pushed outside their intended zone.
If it is the report, try fiddling with the size of the reported-to area, maybe the margins around (what I presume is) the tiled reporting across all the labels drifts from fields resizing/shrinking/expanding...
Perhaps you have a field that is wrapping with empty chars that expand the region to larger than it would seem...
Just some ideas... Good luck!
