Going back to basics for a second:
1. What is the format of the cells in Col A? Are they Currency $? Try changing to numbers.
2. What is the format of the cell where the sum is done? Again check it's currency or numbers.
3. Is each number on the right or left hand side of the cell (with cell formatting alignment set to general and bottom)?
If it's left, then it's in a text format, and if right it's a number format.
4. Try the suggestion in my previous suggest but make sure that you format Col B as numbers including the sum cell for Col B numbers.
5. You mention that your figures in col A are in fact calculation results.
I've been checking over a workbook for adding up hours and minutes, typically using the formula below (inserted into cell F3) to concatenate two numbers in cells D3 and E3 so as to read "number:number (e.g 0:56)"
In the case of the formula above, the concatenate command turns the result into text which meant I could not sum the results of all the figures in col F.
Therefore to convert them back to figures, I had to amend the above formula in F3 to:
Code:
=(CONCATENATE(D3,":",E3)+0)
Note how the +0 covers the whole formula using the brackets, and not simply a +0 tagged onto the end.
HTH and let us know how you get on.