My IP address may well stay the same normally but it cannot be guaranteed with DHCP. I need the connection to support out of hours system maintenance and if I have to log on at 2am only to discover I can's get VPN access as NTL have changed my IP then I'm in deep trouble, leaving me with the option of taking the drive to work (an hour away).
I think my best bet is to try and persuade my employers against static IP security.