Odd Default Gateway Address

Hi!!

I use CISCO Catalyst 6509. And, My PC use WinXP.

Default Gateway Address is 172.16.4.200.

But, in case that default gateway address chage 1.1.1.1, communication with
other segment is O.K.

I think that Communication can't establish to other segment.

When i look at the ARP Table, the MAC address of 172.16.4.200 and 1.1.1.1 is
same.

How do i correct this problem??

Thanks in advance!!

interface [YOUR GATEWAY INTERFACE OR VLAN]
  no ip proxy-arp

-Chris