Related to this sort of MS Security update:
http://support.microsoft.com/kb/3025036/EN-US
This worked for us:
- Open a blank version of excel.
- Disable ActiveX controls in Excel Options.
- Open the offending file. (Click through any error received upon open)
- Save the file as a new name.
- Activate ActiveX controls.
So saving file without ActiveX enabled does something? anyway worked for us.