If the phone and computer use DHCP to get their IP addresses, then ipCam won't work because there's no DHCP server in an ad-hoc network, so the phone and computer won't have ip addresses. You should be able to get it working on an ad-hoc network by manually setting unique IP addresses on the phone and computer (usually something like 192.168.0.2 and 192.168.0.3, respectively) and setting them both to use the same subnet mask (usually 255.255.255.0).
