BB 9900 browsing not working since Carrier Service Update message

Hi, so I'm no guru but I consider myself an advanced technical user. Got a bit of an issue here which even my Carrier is stumped - they're currently suggesting replacing my handset which may resolve the issue but seems a bit extremem to me.

Basically, the device was functioning fine up until yesterday when I received a Service Update which I duly carried out (read, delete text, reboot). After that, internet browsing ability ceased. Email however continues albeit much much slower.

If I connect on wifi however, I am able to browse although images in aps like Facebook won't load - very strange. I spoke a couple of times with Tech. Support and we've tried resending Service Books, re-registering the Host Routing Table and full reboots. None of that worked.

My hunch is and given the inconsistent nature of of the issue is that the problem lies in the Service Books or HRT somewhere. Does anyone have any view or has had a similar experience?

Details:
Carrier: Orange UK
Service: BIS
Device: Bold 9900
OS: 7.0 Bundle 2406
HRT GW: 206.51.26.197