Well that's a new approach.
You just have to 'dhclient <interface>' in BT4
There are a bunch of threads on the subject.
i couldnt figure out how to do the dhcp thing on bt4 so i started my bt3 cd and copied dchpcd to the hardrive then copied it to the /sbin on bt4 and it worked like a charm.. it just sucks having to copy it.