My work VPN is on 192.168.1.xx.
My BT HomeHub is on 192.168.1.254 and I need to change the relevant IP range(s) to 192.168."not 1".xx so that it does not conflict.
My work IT Specialist was able to change my BT HomeHub to 192.168.12.xx in Jan 2010 and it worked for several months.
It was then reset at some stage.
Since then my work IT Specialist and BT phone help have been unable to change it.
This problem must be common for people with a BT HomeHub who wish to log into their work computer.