Interesting Windows 2000 Issue

We have a client who runs a Windows 2000 ISA server (runs 2000 server and ISA 2000).  This server of course has 2 NICs, one for outside and one for inside.

Just a week ago, she said that when she came in, her NICs had lost their static IP address assignments and were showing the default IP assignment (169.x.x.x, you know what I mean).  Of course this means that the NICs could not get any DHCP addresses.

So she put the Static IPs back on, but here is the issue.  The ISA IP filtering logs show that UDP port 67 and 68 are being blocked (source IP of the server and dest. is the broadcast address) constantly, those ports are used for DHCP.  It appears that the NICs are still trying to get DHCP addresses?

My question first is, how is it that the NICs could lose their Static IPs like that?  The woman insists that there was no way anyone had access to the server over that weekend, so it must of been some kind of failure.

My second question is, why would it seem that the server is still trying to get DHCP addresses?  Has anyone come across this before?  These blocked packets only started appearing after the odd server error mentioned above.

Thanks for the input.