The Blog Copyright plugin wasn’t inserting the copyright information within the footer – it was adding it beneath the WRAPPER. Using CSS, I was able to re-position it within the COLOPHON…but this only worked for monitors with a resolution matching my own. (Larger resolution screens displayed the copyright somewhere to the left of the WRAPPER.)
Footer Putter inserts the copyright directly into the COLOPHON, and should not experience this problem.
(An additional advantage is that Footer Putter is being updated by its developers more frequently than Blog Copyright, and therefore may be more secure.)