Congratulations! What was a reason, BTW? Answer please. Answer to you question - I think the new "APN tmo-mms" is needed for fMMS only, just to know where is the server and follow gateway rules (it may be VERY specific for MMS only). But you should use a regular cellular connection for the rest of phone software. Don't bother with gateway ("APN" in "Setting/Internet connections") from your new tmo-mms for 3G connection - it would decrease your bandwidth. Again, I suspect your new tmo-mms defines gateway only for fMMS usage.