If you suspect a add-in/plug-in, then you can disable it and try Excel again.
Choose Add-Ins from the Tools menu. Excel displays the Add-Ins dialog box, and your deleted add-in should still be listed as available.
Select the check box next to the add-in you want deleted. Click OK and confirm the deletion.
This should disable the add-in for Omnipage or any other add-in/plug-in.