I use Excel 2003. I had found out how to solve the problem about Ctrl-End
going outside the used range, by doing Edit/Delete and File/Save As.
But today, when I was cleaning up my spreadsheets, I started having the
problem on some spreadsheets, and the usual methods did not always work. In
fact, some of my spreadsheets were right when I opened them, and I after
doing some cleaning up, they were wrong, and couldn't be fixed.

By checking the Ctrl-End position after every time I did something, I found
out it was because of cell borders. These spreadsheets ended up with cell
borders turned on randomly on cell, rows, and columns. So I was clearing all
borders, putting on under the first line, and turning on grid lines in print
setup.

Suppose the last cell was F10. Then when I cleared it's borders, that also
cleared the borders of the cells next to it, so they were then considered
part of the used range.

What worked was to select the used range, then in the boders, choosing the
Outline option.