So far, this is still “up in the air” and I have no direct answer on the subject. Therefore, take this information as you will 🙂
This week we installed a new server in our office as the old one was getting overworked. (Much like myself). The new server is running with 2 x 2.8Ghz Dual Core processors. I initially had this set to use Multithreading, and therefore Windows 2003 Server detects this machine as having 8 processors.
Everything seemed to be fine with the Swing Migration until I got to the stage of Installing ISA 2004 on the new SBS2003 install. I noted that the ISA services were stopping, and it gave all the symptoms of Microsofts Article 884569
Of course, what was odd about that is the fact that the ISA 2004 install that comes on the Premium Technologies CD includes ISA 2004 Service Pack 1, so this issue should not occur.
It seems to me that Service Pack 1 for ISA 2004 does not correctly detect Dual Core Processors with Multithreading enabled. So for the moment, I have removed ISA until we get a fix.