The issue has now been resolved.
As I am a corporate customer I had someone look at the SIM and they reset some things centrally.
I then had to put the data SIM into my Nokia E71 and possibly importantly* browsed a couple of pages on the web. This transferred some settings onto my SIM. I then transferred the data sim back into my K4505 dongle and now it works.
* I tried this once before but it didn't seem to transfer all the access point/user name and password info onto the SIM. Whilst I had it on and got a valid network I didn't browse the web on that first occasion. Without this information a connection was made but I wasn't getting onto the network and getting an IP address assigned.
So for me these were the steps I had to take to resolve.
1) Install latest VMC (9.4.6 at the time of writing)
2) Install VMWare Hotfix
3) Get someone to change some settings on the Data SIM
4) Put data card sim into my nokia E71 and then browsed the web before returning SIM back to K4505 dongle.
I therefore think there were three issues at play
1) I am using Windows 7 64bit
2) I have VMWare Workstation installed
3) My SIM got corrupted somehow
Anyways the issue is now resolved. Many thanks to all of you who assisted me in getting to a resolution.
Cheers, James
P.S. One piece of feedback - the fact you guys can't look into corporate customer accounts and help with the SIM part is a bit pants. I am a vodafone customer not a department of vodafone customer. The fact you guys hit a wall internally in trying to help me is something that should be resolved. That said I really appreciate the fact that you did everything you could do to resolve my problems - I do understand "the system" let me down not you guys on the front line!
Cheers, James