hmm...oh YEAH!!! you're the one who posted the thread on OT about your hate for dell. i totally agree with you on that...
topics aside, WTF is up with your mobo? it reverts to 1x for absolutely no reason. go into windows, download a program called "cpu-z" and in one of those tabs in the program, it'll say what pci-e mode it is running on.
but yes, DEFINITELY enable hyper-threading. thats basically a good reason why the prescott core p4's are still alive (joking of course and not wanting to start a flame war). you will see a boost in multithreaded programs (latest version of winrar, photoshop, quake 3/4, cod2, etc) and probably overall performance as well. and your FSB will raise from 533FSB to 800FSB.