New laptops get no address the morning after DHCP snooping goes live

Last night's change enabled DHCP snooping for VLAN 20 on access switch ASW1, with the uplink Gi1/0/48 trusted. This morning, laptops arriving in VLAN 20 end up with 169.254.x.x addresses. Desktops that stayed on overnight still work. DSW1 is the gateway (10.20.0.1) and runs the IOS DHCP pool for VLAN 20 itself, with a one day lease.