Thank you! That fixed it (so far).

For future references, this is how I solved the problem with Excel 2007

StartRun
Type "Regedit" (no quotes)

Find the file HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\E xcel\Options

****note, I have 12.0 written because that is the version that I am
using. If you have a different version, replace 12.0 with the correct version
number.

Right click to create a new DWAROF value. Name it: FullCalcOnLoadOldFile
Leave the value as 0 (zero).