the thing i don't get about your carrier bundles is why does your custom vodafone carrier bundle say it enables MMS when the latest iPhone firmware already enables MMS?
also if something goes wrong with a person's iPhone after they install a custom carrier bundle, will the iPhone warranty cover the repair?
MMS requires the data networking to be setup, and frequently the data traffic is sent to a separate GGSN (SGSN?) from the one providing the rest of the data connections. It makes it easier to charge flat rate per message instead of the per byte rate on the GGSN with an internet connection.
So, if the main data connection is going through one point, and the MMS' are sent through another, it won't work until the carrier settings are correct.

