Well for starters you want to make sure all your voltages are in check if you are getting instability. Your memory should be running at its rated voltage- depending on what it is that can change, for instance Crucial Ballistix has 2.2v rated voltage so thats what you should be running it at, if you are running at 1.9v 800mhz+ as one of your pics suggests then you might want to change that. Additionally if you are Overclocking by raising the HTT then you will also need to raise the HT link voltage (should be in BIOS) and if it is going above 1000mhz (HTT frequency x HT multiplier- yours is set to auto most likely 5x) you will likely get some instability, its best to keep this between 800-100mhz. I am not familiar with the standard Vcore for OC's on the 6400 BE as I think its a 90nm based CPU and my 5000+ BE is 65nm so they have different Vcore's however I've seen that 1.4v-1.5v has been fine as long as your load temps are in check (with a TR120E I'd say they should be around 50c tops?).
Given that you have a Black edition if you haven't already the best way to go about it is to start at stock settings, raise memory voltage, set cas timings manually, then just simply raise the multiplier- load windows, run Prime 95 and if its fine raise multiplier again rinse and repeat until you hit instability then simply raise the Vcore. This way you are not stressing the HT bus by going above 1000mhz (a cause for possible problems) and keeping the memory at its rated speeds so you eliminate 2 factors that lead to instability, and all that remains is the CPU which would just require a higher Vcore.