Wireless networking on vista doesn't get a valid DHCP IP

When trying to connect to the UCLAWLAN, the IP obtained would be 169.254.×.×. This is sign that the machine cannot reach the DHCP server.

From Microsoft’s knowledgebase article on this.
Consider the following scenario:
• You connect a Windows Vista-based computer to a network.
• A router or other device that is configured as a Dynamic Host Configuration Protocol (DHCP) server is configured on the network.
• The router or the other device does not support the DHCP BROADCAST flag.
In this scenario, Windows Vista cannot obtain an IP address.

This issue occurs because of a difference in design between Windows Vista and Microsoft Windows XP Service Pack 2 (SP2). Specifically, in Windows XP SP2, the BROADCAST flag in DHCP discovery packets is set to 0 (disabled). In Windows Vista, the BROADCAST flag in DHCP discovery packets is not disabled. Therefore, some routers and some non-Microsoft DHCP servers cannot process the DHCP discovery packets.

See Microsoft’s knowledgebase article for the solution: