Mike
a) Go here and test your exchange installation.
http://www.testexchangeconnectivity.com/b) It might be a good idea to download Exchange 2003 BPA and check your exchange configuration
http://www.microsoft.com/downloads/details.aspx?FamilyID=dbab201f-4bee-4943-ac22-e2ddbd258df3&displaylang=enAfter installing BPA - run a health scan.
In reports - check radio button for informational items.
You can upload the reports here..
b) Check this article from alanhardisty. This has worked well for me.
http://www.experts-exchange.com/Software/Server_Software/Email_Servers/Exchange/A_1798-Exchange-2003-Activesync-Connection-Problems-FAQ.html?sfQueryTermInfo=1+30+activesync+iphon