Do you have any add-ins enabled in Outlook 2010? If so try disabling them and see if this corrects the issue.
Outlook 2010
- File-> section Options-> section Add-Ins
- At the "Manage" dropdown list at the bottom select which type of add-ins you would like to enable/disable
- Press "Go…" and make the changes
- For some add-ins you’ll need to restart Outlook for changes to take effect.