DNSCache service in Windows XP

Hi,

I noticed that the DNSCache service (DNS Client) on WinXP always uses the same source port when sending DNS queries. This behavior is opposed to the one in Windows 2000, in which each DNS query has its own source port.

Does any one know how I can revert to the behavior of the DNS client on Win2k, and have the DNSCache service use a different source port on each query ?

Thanks.