Hardware :: No WAN Ethernet Detected - TC Cannot See Cable Modem

I've got an issue with my TC setup, I cannot for the life of me get it to see the cable modem and setup the WAN access. If you will pardon me I will cut n paste the lengthy description I left on the apple support list as I feel it is pretty thorough. I think I know my way around networks and dhcp but this setup doesn't yield any logs so I can't troubleshoot! I'm on Virgin Media 20megs and I can't connect using my brand new TC.
Modem: Ambit 256
Time capsule : 1 tB, firmware 7.5
Test router : Netgear WGR614V9
MBP alubook 15 inch late 2008

I tried connecting with the test router and the MBP alubook to the modem and both can pickup the ethernet connection and get a DHCP lease after some coaxing (cold-start the modem first, then cold-start the router/mbp). But I'm having no luck with the airport extreme base station. Hard reset / factory reset / soft reset, any startup order, nothing works. I even left the devices offline for an hour before doing another round of testing. I tried several cables (including a crossover cable) and all configurations work apart from the ones involving the time capsule. Both the modem AND the TC ethernet ports light-up with a green light... but somehow the TC doesn't negociate its DHCP or even basic ethernet connectivity. I see there's a firmware 7.4.2 on the support site for the TC but I'd rather not downgrade the unit.

Here are the console logs from the MBP when it connects to the modem (yes, my MBP is named awesome, because frankly it is):
Originally Posted by System.log when connecting MBP to Modem
29/12/2009 08:54:04 Awesome kernel Ethernet nvenet: Link up on en0, 100-Megabit, Full-duplex, Symmetric flow-control, Debug 796d,0000,0de1,0005,45e1,0000
Originally Posted by Modem status page
Cable Modem : Euro-DOCSIS 1.0/1.1/2.0 Compliant
MAC Address : <<redacted to protect the innocents>>
Serial Number : 0014A49B00A5
Boot Code Version : 1.1.2c
Software Version : 2.111.1002
Hardware Version : 1.9