Last Column Error

if we are on the end row, Singularity assumes we are one column less than we should be. 

e.g. if our grid is 3 6 3, then we have 3 columns. We want to be in the last position so that would be 3 (column count) - 1 (the span) + 1 (since we do math our way, not computer-way) = 3. BOOM.