One of the biggest problems with newer Samsung phones (A600, A620, etc) is that they have not been able to do a manual (##3282) provisioning of Vision services, until it has been provisioned OTA. This has created a painful Catch-22 for many, as the most common problem with data services is the initial provisioning.
The exact reason that this was done is still not clear, but we have figured out how to get around it, as described in the steps below.
Dial 47*869#1235 on your handset. At the screen that appears, dial 283.
Press 1, then #. The value should change to something like 1__ from 0__. When this is done, pull the battery from the handset, and restart the phone. You should now be able to provision your username from ##3282.