At long last!!!!!!!!!!!!! It works!!!!
I now have one set of fully working settings for both MMS and internet. I thought they would not send my MMS to begin with but I had to turn the 'Mobile Network' setting on and it worked straight away.
This worked for me so you may as well copy what I did.
1. Delete all of your existing APN settings and restart your phone.
2. Input these APN settings:
NAME: O2 UK Postpay
APN: wap.o2.co.uk
PROXY: <Not set>
PORT: <Not set>
USERNAME: O2wap
PASSWORD: password
SERVER:
http://mmsc.mms.o2.co.uk:8002
MMSC:
http://mmsc.mms.o2.co.uk:8002
MMS: PROXY 193.113.200.195
MMS: PORT 8080
MCC: 234
MNC: 10
APN TYPE: <Not set>
Press 'Menu' and select 'Save'.
3. Now restart phone again.
4. Switch on 'Mobile Network' and test it. Should work perfectly!!!
As mentioned before, in order to send/receive large images you may have to use 'Handscent' but I have not tested it yet.
Hope that cheers you up Magicmat!!