You can ignore the multiplier, it's locked internally on the CPU anyhow.
You must set up in User Defined mode & Ignore Errors.
The FSB speed should be set to 100MHz or more.
The AGP speed should be set to 2/3 of the FSB (not 1/1)
The Voltage should be 1.65V for Celeron2 - unless you're overclocking.
Having sweated out some of the exact same issues with my (3) BP6 systems, in taking them to the next preformance level, I can totally relate to your frustration! Glad it was that simple. Give a post if you're able to run any OC speeds past 100FSB.
I had to retire my HPT366 controller from duty & go with a Promise ATA100 card on both my Cele2-1100 & P3-1100 systems before they would run stable.
I will only use the HPT366 for read-only devices on these systems from now on! Too many crashes & lockups before I did this.