You have to edit the REG to get MMS to work on Alltel. You may also have to call Alltel and ask them to reset your MMS. The setting are
Server Name: AlltelMMSC
Gateway: mms.alltel.net
Port Number: 8080
Server Address: http://mms.alltel.net/servlets/mms
Connect via: Alltel Wireless
WAP: 2.0
Go in to the reg and change all of the settings for Archsoft to .net anywhere you see .com and then reboot and you should be fine.