Question : Outlook 2007 - Connection to Microsoft Exchange is unavailable, when creating calendar items?

We are using RPC over HTTP with exchange 2003, and using outlook2007, the client sets up fine, and when its setup, it says at the bottom connected, we receive email just fine, and we can see existing calendar and contacts fine, but we cannot add new calendar events or new contacts, with getting an error popup in the lower right corner,
The connection to microsoft is unavailable, outlook must be online or connected to complete this action.
I started out with outlook 2010, and thought that was it so uninstalled, rebooted, and installed outlook 2007, tried that and got the same error message, then tried to use a different user, on same computer, same problem, then tried a different computer, and same problem, So I think it is a server issue?

Thanks for the help

Answer : Outlook 2007 - Connection to Microsoft Exchange is unavailable, when creating calendar items?

On the client computer with outlook

Go to Start>run>cmd

Type this

RPCPing.exe -t ncacn_http -o RpcProxy=fqdn.yourdomain.com -P "testuser,yourdomain,testpassword" -I "testuser,yourdomain,testpassword" -H 1 -u 10 -a connect -F 3 -E -v -3 -R none -q

where fqdn.yourdomain.com = FQDN
test user = user
yourdomain = domain
password

Explanation of switches.

http://support.microsoft.com/kb/831051

Please post back results.