I have a multi-tab budget worksheet. I run XLS03, no macro.

Now, after opening the file, when I enter a number in a cell in one of the
tab, the number appears on the other tabs at exactely the same cell
location. It happens on 4 tabs out of 8 in total. It's like all 4 tabs are
the same sheet but no links exist between them, at least not where I enter
the numbers. (links exists in other cells). It simply overwrite the other
cells. But all 4 tabs have initially the right numbers and formula in them.

I've tried to save the file under another name, open the file on a colleague
PC running excel 2003 also and I get the same results.

Previous version of the file do not show such behavior. Since tons of
changes has been entered between the actual and previous version, I
obviously don't want to go in the process of rebuilding the model.

Only visible sign of something different is that after the name of the file
in the title bar, now it's written Workgroup although I never save under
anything else than XLS file.

Any ideas ?