PXE Booting: "No entry found in database for device."

[e-j]

[FONT=Tahoma]After not using FOG for a few months, PXE booting no longer works on the subnet our FOG server resides on (172.20.3.0/24). PXE gets a response from DHCP but returns [/FONT][FONT=Tahoma]“No entry found in database for device”. The same machine on a different subnet is greeted with the FOG menu. The scope options in DHCP are identical for both subnets. [/FONT][FONT=Tahoma]We’re running FOG 0.32 on Ubuntu Server 12.04.2 (IP: 172.20.3.88) with separate servers providing DHCP and DNS.[/FONT]
[FONT=Tahoma] [/FONT]
[FONT=Tahoma]Windows Server 2003 DHCP (172.20.3.55)[/FONT]
[FONT=Tahoma]Scope option 066 = 172.20.3.88[/FONT]
[FONT=Tahoma]Scope option 067 = pxelinux.0[/FONT]

[FONT=Tahoma]I was able to verify that TFTP is accessible from this subnet:[/FONT]
[CODE]>tftp 172.20.3.88 get pxelinux.0

Transfer successful: 16967 bytes in 1 second(s), 16967 bytes/s[/CODE]

[FONT=Tahoma]Any input would be greatly appreciated.[/FONT]