SQL Server 2005 SP2 question:

The SSMS "Activity Monitor" provides a column "Net Address".
In most cases, this is the MAC address of the client's ethernet card.
In some cases, it is all zeros, and the "host" column contains the
client's IP address.

In some cases, the "Net Address" value is just bogus.
Furthermore, when I connect to a SQL Server 2000 instance,
from the same client machine, Enterprise Manager displays the
correct MAC address.

Has anyone else encountered this?