Excel 2002 (10.6823.6825) SP3

I imported data from large tabbed Word file.
File was decades of financial ledger data with yearly totals.
After import it appeared perfect.
I moved manually added totals to other cells to compare later.
I put in first formula to simply sum some cells and it got 0 where is should
have been thousands.

I searched groups and tried all kinds of copy, paste-special with multiply
of 1 and it all failed. Then I notice simple format of cells is not really
working. I can format to put in and out comma separation and it "does it"
with out actually affecting the data in the cell (eg no $-sign change, no
comma change).