Steps to reproduce Enter the following: A1: 1 B1: 1 C1: SUM(A1:B1) C1 displays 2 (OK) Now: Right-click on C1 header; select "Insert columns on the left". Blank column C1 appears, the sum moves to D1. Click on D1, press F2 to edit formula and change B1 to C1 (now formula is SUM(A1:C1) Go to C1 and enter "1" for the cell. Sum in D1 remains unchanged (2 instead of 3), only until force re-calculate D1 using F9 key. Win7/64. OpenGL enabled.
*** This bug has been marked as a duplicate of bug 111428 ***