MMS on non T-mobile networks?

[grenness]

I'm having a hard time configuring MMS on my G1 - It's SIM unlocked and I use it with the Norwegian operator Ventelo - although I won't expect anyone here knowing exactly what config works with Ventelo which you probably have never heard of...

However, as you know there's a number of different settings/options where I'm supposed to enter the correct operator info to make MMS work.

My first question regarding my options under
Settings->Wireless controls->Mobile networks->Access Point Names
is whether I must have one "file" for general data connections and one "file" for MMS, or if a single "file" should cover everything?
I notice in the list of built-in APNs that for some networks there are one data APN (like T-Mobile A "gprsinternet") and one MMS APN (T-Mobile A MMS "gprsmms"). Is that like an industry standard?

And regarding all the different options in an APN file;
APN
Proxy
Port
Username
Password
Server
MMSC
MMS proxy
MMS port
MCC
MNC
APN typeCould someone explain the different ones - do they sometimes go under different names?

So far, the only help I've gotten from my network operator, is to try the following settings:
Description: Ventelo MMS
Connect to: WAP network
Access point: mms.ventelo.no
Username: ventelo
Password: 1111
Authentication: None
Primary DNS: -blank-
Secondary DNS: -blank-
IP address: -blank- and a sort of example config if I understand them correctly:
Name: Ventelo MMS
MMSC-URL: http://mmsc/
WAP-gateway: 10.10.10.11
Port: 9201
Connect via: WAP netwoek
Max. send size: 300K
WAP version: WAP 1.2 / WAP 2.0
But trying to put these values in different places in my APN, both trying to have two different APNs for data and MMS, and combining all in one singe APN doesn't help me get MMS to work. I can neither send MMS's nor download MMS's

Any help or tips would be greatly appreciated!

Thanks,
Christopher