This chatter about the "SPD" is a bit confusing.
The "SPD" is the default timings the RAM uses, they can, in most OCable MBs be altered.
In your case, to the OP, you'll likely be fine with the SPD settings since your default DDR2 800 setting and the room your RAM has to increase in speed should work out fine.
Once you find out how high you can get the CPU and RAM speed @ 1:1 you may be able to tighten the SPD timings if necessary.
BTW, take a look at ddr2-ram-dividers
You can see what the various changes in speed are dependent on the CPU multiplier and divider. Even though you won't likely need a divider unless you drop your CPU multiplier a lot. The chart is helpful to get the understanding of what happens with various timing, multiplier and dividers do to the RAMs relative speed.
BTW, a 5600+ @ 3.3 is a very good OC, nice work Edited by The Duke - 6/25/08 at 6:57am