First, calm down and we'll step through this
The temp probe should not ever be trusted on this board. What HSF are you using? This is going to be a very big portion of your overclock. Second, are you still using the gawdawful stock aluminum hood ornament on your northbridge? While the C1 stepping is better, it will STILL BE LIMITED if you use that piece of junk.
What I need to know in order to help you are the following (yes, this may be a pain):
1) Full stepping of your chip, such as:
AXDA2100DUT3C 9724884280420
JIUHB 0308VPMW
This will assist in determining what you are capable of. Not all chips are created equal. You will need to remove your HSF in order to check this.
2) What settings you are using in BIOS. The primary ones are as follows:
Multiplier, CPU Interface (Optimal/Aggressive), FSB Speed, Memory Timings, All Voltages, CPU Throttling (OFF!!!), AGP freq (66), Memory Speed (100%), and Spread Spectrum (OFF!!!).
3) What HSF are you using and what temps are being reported. What type of grease are you using?
4) What speed is your RAM rated for? If it is DDR400 rated at 2-2-2-6 (Corsair XMS LL) and you are running it in Dual DDR at 2-2-2-5, you may be capped at only 190-200 Mhz. You may need to increase your timings. Remember, while your RAM is guaranteed to run at its rated speed (and will be replaced if it can not), it is not guaranteed to run any faster, especially if you are using lower timings and running in Dual, which tends to lower your max stable FSB.
5) What is the max speed you can run stable? What is the fastest that particular chip has run (raw Mhz)? What is the fastest your RAM has run in Dual DDR (FSB & Timings)?
6) Why are you still using the stock NB cooler (if you are)? No, seriously ... I gained a massive amount of stability when I swapped mine.
7) Have you tried the processes I outlined in my article?
http://12.18.239.202/heatercores/primer.htm
This will teach you alot about what your parts are capable of.
8) Have you tried disabling some of the peripherals that you aren't using such as the on-board firewire or SATA? This sometimes adds a small amount of stability.
9) What type of PSU are you using? If you are using a weak azz 300W unit you are screwed. You need at LEAST an outstanding 350W unit and most times a good 400W unit to power an overclocked NF2/TBB setup. I'm running a 480W and a 500W on mine and I still get a few minor spikes here and there. This could be a massive factor in your stability.
10) Are you in an older house/apartment? Ghetto wiring can cause nasty things to happen with your power and can limit your OC.
When you can answer these, I can troubleshoot you. Until I have the full story, however, it is virtually impossible. I don't know why, but I have had the feeling over the course of these posts of yours that you're holding something back. If you are, please enlighten us on the whole story so we can do our best for you.