Vista - Windows Vista SP1 client not getting ip address from Cisco 3750 switch

Last year, I configured a dhcp pool on a 3750 switch for a lan party at
work(I work for a university and part of the students activities). No
problems all worked fine with Vista.

It was time for the lan party again at work. I put the dhcp pool back on
the switch but the Vista clients would not pull an ip address, but when I
did a sh ip dhcp binds it showed their macs were bound to the ip addresses.
The Vista client all had auto configure 169.254 addresses. I tried some
things, googled and got some registry hacks we tried for the tcp system
parameters but no luck. I took my Helium Spetrum Analyzer running XP and it
got an address so I know the switch is configured correctly.

For the work around I made the int vlan ip address 169.254.0.1/16 updated
the switch settings and the lan party is going down.

I found some vague references to this problem on my google searches, but
nothing solid.

Is there something that needs to be done on the clients to pull an ip
address from the dhcp pool on the switch? They pulled an ip address from
their helper address to the QIP DHCP server? XP machines work with no
problems.

Thanks,