K800i on uk T-Mobile Cannot set up gprs or mms

Posted by 789
Have a new K800i (was on O2 network and simfree) but used on T-Mobile (UK) now.
Cannot get the WAP (GPRS) to work
Have tried through Sony Ericsson web site, getting them to send settings which gives failed to connect message when I try to send MMS or get on internet.
Also tried through UK T-Mobile site (getting them to send settings)
Spent 1/2 hr with T-Mobile phone help with no success.

Can any kind person suggest where to go now or what to set up as its driving me up the wall.

Posted by 789
Solved it

it was on T Mobile side
Tried my T Mobile sim in K800 and all worked OK,got onto internet and MMS
Tried Her T Mobile sim in my other phone and lost internet & MMS

Had major problems getting T Mobile at first to except it was them and not phone.
They did find set up problems on their end and now all works great