Remove BUSY status DHCP Leases to solve malfunction of DHCP server

From MikroTik Wiki

Known Issue

We've experienced problem with windows vista not receiving the DHCP and sometimes I think it is related to the DHCP server that will be filled BUSY task of assigning IP addresses to ZERO (00:00:00:00:00:00) Mac address which will never go away until it expires and may stays there if there is a client keep requesting.

we had to over come this by an script that had to be running as schedule every 1 minute to check dhcp leases and remove them. I hope in next version of Mikrotik it will be solved although we haven't ugpraded 3.0RCx yet.

code:

 :foreach i in=[/ip dhcp-server lease find mac-address=00:00:00:00:00:00]\ 
 do={
 :log error ("Mac address zero detected: " . [/ip dhcp-server lease get $i address]);
 /ip dhcp-server lease remove $i;
 }