I have your P4DCE+II with two Xeon 2.4GHz CPU's (400FSB). During boot up I get a BIOS error message saying "Warning: non matching MP Processor" and indicating that I don't have the same model and/or frequency, but I checked and they are both the same. What is wrong?
The problem is that you have two different "stepping codes" of your CPU's, this is called Mixed stepping, you can check the stepping codes on the Intel site with the SLxxx code from your CPU. Not all combinations of stepping codes are possible, so please go here for more information. Please contact your processor supplier, to get the proper CPU's for Dual processing.