Yes, it does. DDR2 won't be able to reach those speeds without massive overclocking, causing possible stability issues.
What I'd recommend: (Taking it that you are running at a 8x or 9x clock multiplier)
If the clock mulitplier is 8x, set the FSB to 400MHz.
If the clock multiplier is 9x, set the FSB to 356MHz.
This will give you a CPU speed of 3.2GHz without stressing the RAM at 9x. 8x with a 400MHz FSB means working at the RAM limit, so if you're not comfortable with this, feel free to drop down to 380MHz or something.
Also, keep an eye on your CPU temps. An aftermarket cooler should keep it in spec, but the stock cooler might be too small.