If the GUIDs are different, there is a larger issue. Namely we're looking at the wrong computer in SMP. SMP relies on the GUID as the primary association between the client and the server. Approaching this from a "Needs Attention" perspective may be jumping the gun a bit.
Keeping the same computer, get its GUID. Then replace {GUID} in the following link and use the link from the SMP server.
http://localhost//Altiris/Console/Dashboard/DashboardView.aspx?ResourceGuid={GUID}
This should take you directly to the Resource Manager page for the computer. This may shed some light on what this computer is (different name, etc.). It may also show that this computer is checking-in normally. If so, we need to locate the computer that is actually failing.
Let us know.