Windows XP Firewall Soure port filtering??

1. Windows XP Firewall Enable

Windows DHCP Clinet ----------------- External DHCP Server
(dhcp request)
- source port: 68 ----------------- received ok.
- dest. port : 67

(dhcp ack)
received fail ----------------- - source port: 8000
- dest. port : 68

Question. The external DHCP Server uses 8000 send port according to security
policy.
I think Windows Firewall blocks 'dhcp ack' using source port
filtering.
Can I disable source port filtering?
If it's possible, plase let me know how to to it.


2. Windows XP Firewall disable
Both receive ok.

3. Winodws Vista Firewall enable
Both receive ok.

I appreciate your help in advance.

- Dany