Here is some information from another site on early dial:
Early Dial means that the BudgetTone sends for each pressed digit a SIP INVITE message to Asterisk. Asterisk looks into its extensions and, if no match happened yet, it sends back a “484 Address Incomplete” message. Otherwise, it executes the action.
I also have the problem on another server where I am using Asterisk 1.4 on a new install.
The server above where I only upgrade freepbx is an Asterisk 1.2.18