I have read through that KB article and it does seem to partly fit my situation in that we do see cisco vpn systems disappear from view. Our global admin team does not feel comfortable implementing the solution listed. To me that insert statement seems harmless.
That KB does not cover how to write the insert statement for systems that do not report a MAC address and in turn report a "blank" MAC address.
it is strange to me that the MAC address is "blank". I guess the next question is what value is the database storing when a blank MAC is seen under system properties? Is it 'null' or some other value?