Hi
I'm guessing there's some code running that's doing this.
After you've opened your workbook, right mouse click on a sheet tab, and
choose view code. On the left hand side of the VBE window (under where you
see your workbook's name in bold) you'll see ThisWorkbook - double click on
it and some code should come up on the right ... i'm guessing your problem
is in there.
Cheers
JulieD