Prøv at disable office plugin'en i Norton.
http://support.microsoft.com/kb/329820Norton AntiVirus 2004, Norton SystemWorks 2004, Norton AntiVirus 2003, Norton SystemWorks 2003, Norton AntiVirus 2002 or Norton SystemWorks 2002 Is Installed
Disable the Norton AntiVirus Office plug-in program. To do this, follow these steps: 1. Start Norton AntiVirus. To do this, click Start, point to All Programs, point to Norton AntiVirus, and then click Norton AntiVirus 2002.
Note If you installed Norton AntiVirus as part of the Norton SystemWorks 2002 program, click Start, point to All Programs, point to Norton SystemWorks, point to Norton AntiVirus, and then click Norton AntiVirus 2002.
2. Click Options (in Norton SystemWorks 2002, click Options, and then click Norton Antivirus).
3. Under Other, click Miscellaneous.
4. Under How to keep Microsoft Office documents protected, click to clear the Enable Office Plug-in check box, and then click OK.
5. Restart the computer.