|Overclocking should be done thru the BIOS, not thru a software program, even if it is supplied by the board manufacturer.|
Personally, I try not to use use the term FSB as it's not real...it's basically a marketing term. You should be talking about the various frequencies. For example, 800MHz FSB actually runs at 200MHz frequency...1066MHz FSB actually runs at 266MHz freq...1333MHz FSB actually runs at 333MHz freq, & so on. Same goes for RAM...DDR2-667 runs at 333MHz freq, DDR2-800 runs at 400MHz freq, DDR2-1066 runs at 533MHz freq.
You never listed which CPU you have, only that it's default speed is 2.4GHz. I can only guess that it's clock settings are 9 x 266MHz? If you bumped up the speed to 2.6GHz (which is an extremely minor overclock), you probably increased the frequency to about 289MHz? But what you need to realize is that there's a domino effect...when you increase the CPU frequency, you also increase the RAM frequency, PCI frequency, PCI-express frequency, etc. And to prevent them from going too far out of spec, you need to enter the BIOS & make some changes. You need lock the PCI & PCI-e at their default speeds. There is no benefit to overclocking them...all it will do is cause instability.
You should also strive to maintain a CPU:DRAM frequency ratio of 1:1. What that means is that if you run the CPU freq at 289MHz, the RAM should also run at 289MHz. If doesn't matter if you have DDR2-667, DDR2-800 or DDR2-1066...it should be scaled back to match the CPU frequency.
There are other BIOS settings that should be addressed as well...EIST, Spread Spectrum, RAM timings, voltages, etc.