After doing some research the turn off mobile data feature on the Desire (and some other phones) allowed for MMS messages to still come through as normal. I think it disables data for everything and then turns it on automatically if a MMS comes through or something like that.
The problem is it turns out that most android phones cannot do it that way. And if you turn off mobile data it prevents the use and retrieval of MMS (ether automatically or until its turned on or the mms stops trying to arrive – I believe).
Before everyone says leave it on, or it doesn’t reduce the battery too much leaving mobile data on 100% of the time, even while having wifi left on just seems wrong and pointless.
The problem is that I get charged for mobile data. In fact I keep getting charged for mobile data even without MMS being received. I have for the last few days I've had my Nexus 4.
Basically before (HTC Desire) I had mobile data off 90% of the time, and wifi on 90% of the time. Turning one off when I needed the other for browsing etc and not for MMS. Is there no such way to do this like I'm used to where its toggle one off and the other on, and everything works?
Iv had a rummage through the menus (maybe not all yet) and considered setting restrict data to on; however this seems to prevent me from switching and using mobile data when I need to, as well as preventing background actions such as upload when charging, without having to jump through menus and turn this restriction off.