i have a feeling that for iphone 2g to enable MMS, the only way is to first install the cydia mms2g to enable your sms to have the camera icon, then go to the website www.unlockit.nz/# and create a custom IPN using the setting:

APN:  Net
Username: Maxis
Password:  Wap

Do turn on the V3 teethering and MMS option at this stage, create custom APN, install it to ur Iphone 2G, then you can start to MMS.  I wonder if the IPCC file would change the APN to net instead of unet, maybe that would solve the issue and we don't need to go to the unlockit.nz website to create custom APN.