Anyway, porting went through sweet as and the Xnet guys are so so so good to deal with. Was really impressed with the whole process.
Chucked in the registration details in to Asterisk and assumed all is good. In my stupidity though I forgot to change the outbound route to pick the VFX trunk instead of the 2Talk trunk which still had an 028 number attached so I could make calls out no problem. The problem arose when Mum tried ringing me lol. she couldn't get through. I looked at Asterisk and realised what I had done. So have deleted the entire 2Talk trunk out of there. However, now I am just having no joy with the VFX trunk.
Below is what I have put in to the trunk settings. They are pretty much as supplied by Xnet but I must be missing something...
Trunk name: VFX
User context: **username**
Reg string: as supplied
Any thoughts as to what I might be doing?