No MMS notification on 2g

[Guest turnpike]

Apologies if this has been asked before, I've been searching around and not found the exact issue.

I tend to leave my phone on 2g to save battery. However, I don't get a notication sound or visual when I get an MMS photo sent to me. The text is sitting there unread in my inbox along with a download option (which I obviously use,after switching to 3g, once I realise I've got a message).

Is there an option I've missed somewhere so I get a notification?

Cheers!

Turnpike