Business user with a number of 9800's and working fine until fairly recently where I noticed that when I tried to send a picture message it didn't go and displayed a "message exceeds networks limits" message. Contacted Voda business tech support and they checked all the service books and also resent them. Same problem. Advised me to wipe the handset and setup again. Same issue. Now the message was certainly under the 300Kb but the autoresize didn't work and even when I resized manually it still didn't work. So this problem and the fact that the USB connector was a bit flaky had meant a replacement handset. As Voda have no 9800 in stock I have been given a 9780 Bold until I get my replacement torch. All set up fine but for the MMS still wont send - so thinking that this is SIM (Customer services also checked the bars and said there were none). Have checked message centre number and its fine and Customer services say that nothing stands out as to why the MMS shouldn't be working.
Found the problem. Numerous updates and security wipes and settings changes (thanks to Jamie at VodaUK BB support for the 2hour mammoth call) I have discovered the problem seems to relate to notifysync that we use to connect to the NHS exchange servers. It never used to affect it but somewhere down the updates it now causes the MMS to fail.
MMS worked without Notifysync installed, stops working when it is installed and starts working again when it is removed. At least that the issue identified.