Ben wrote:

Upon installing Outlook 2007 and importing my old data file, the
calendar somehow got messed up. Under "All Calendar Items", "My
Calendars" it shows two calendars: "Calendar" and "Calendar (1)".
Unfortunately my appointments are all in the "Calendar (1)", but the
"Calendar" is set as default, so if peple invite me, appointments
will be set in the wrong calendar.

Never export to or import from a PST. There's no need and it can have
irritating side effects such as you describe. Start with a new mail profile
and simply reuse the PST.
http://www.howto-outlook.com/faq/newprofile.htm
http://www.howto-outlook.com/howto/backupandrestore.htm
--
Brian Tillman