At last thank you so much guys this is great

Here is what i did

UK o2 PAGO phone now using Vodafone Monthly Contract Sim
16gb 3g

Having spent ages trawling the various webpages this is what worked for me

Restored phone using i-tunes to latest 2.2 with the o2 SIM in
Let the phone activate on i-tunes then disconected from PC
Still with o2 SIM in used QuickPWN 22
Once completed disconnected from PC
Connected phone to wifi at home
Used Cydia to add Source from
Searched for and installed yellowsn0w
Installed Bossprefs
Installed MobileTerminal
Went to Settings - General - Reset - Reset Network Settings
Take out and replace the o2 SIM with the Vodafone SIM

It reboots and comes up within a minute or less, didnt have to use Terminal or BossPrefs.

Guys all i can say is thank you for this you work is greatly appreciated