This problem started with seeing a bunch of Event ID 8206 and 8207's in the app event log. After seeing this: http://support.microsoft.com/default.aspx?scid=kb;en-us;905813
I took a look at the properties to see that it has my Exchange 2003 and 2007 servers listed (good, current servers) but it also has my old Exchange 2003 box listed as well that i decommissioned when I upgraded to 2007. People are still able to create and delete appointments in the public calendar, I just need to stop of the errors in the log. I also have the old Exchange 2003 information in my ESM from the decommissioned server, how do I get rid of it once and for all? I transfered all of the roles DC roles before I got rid of it, but I have a feeling there are some exchange roles that didn't get transfered and for whatever reason are just now becoming a problem.