It's a "normal flaw". Happens here, too - yet those machines ARE managed, they are in the SEM console list, they have current policies and defs, and when I go to some of the machines (those I can go to in this building) the client end looks fine, too.
It also reports Cisco devices as running Windows XP and being unmanaged, too - including one of our access points................
In other words, yeah, it does that............ I think I've posted about it in the forums here before.