"Meg" wrote in message
...

I exported my contacts from Outlook 2003 and imported them into Outlook
2007.


There you have the answer. This is why there are constant posts in the
Outlook groups telling people NOT to use the import/export function to
transfer Outlook data.
You probably have corrupted your Mail profile by importing contacts.
Go to Control Panel-Mail-Show Profiles and create a new one. Add the
existing pst file to that profile and see if that helps.