Do you also have problems printing from IE7?
IE7 is causing a lot of printing errors. Most are resolved by reinstalling IE7. Outlook and Outlook Express use the rendering engine from IE, so it may be causing your issue.
If you choose to reinstall IE7, make sure to shut down all background applications first, including Anti-Virus/Anti-Spyware Software. This will reduce the chances of conflicts.
Internet Explorer: Get It Now