Getting the 169.xx IP address all of a sudden

Very weirdly, while I'm working, my MB that's connected via ethernet to a D-Link switch (which is connected to a D-Link router) goes offline. I check network settings and my IP address still says 192.168.1.2 (which is correct) but no connectivity. I then turn off the ethernet and turn it back on (in DHCP mode). It now gets an IP of 169.254.66.86 instead of 192.168.1.2 (which is the address reserved for my MB's ethernet port). I tried changing to DHCP with manual address and it now has the 192.168.1.2 address but cannot ping even the router. A reboot solves the problem but this has happened twice now so would like to find the root cause. The only thing I can think of is that my VMWare Fusion Windows XP host somehow interfered w/ the ethernet on the Mac. But still, if I try to renew the DHCP lease, I'd expect things to work again. I turned off VMWare and then tried to renew but still no luck. The other computers on the same network aren't having any network/connectivity issues. I am able to turn on wireless and there's no issue there. Just w/ ethernet. Any ideas on what might be going on? I recently installed the latest security update so I have all the updates and am on 10.5.5.

One more thing I just noticed.. I removed the address reservation on the router side and renewed my DHCP lease.. weirdly, the MB still shows the 169 address but on the router I see this ethernet port being assigned a 192.168.1.24 address.

Message was edited by: baseliner