Intel's processors are designed to operate at specific speeds. When you run with faster memory (and the BIOS configured to support these faster speeds), you need to understand that you are effectively overclocking the processor's memory controllers and this can have repercussions. First of all, the definitions for the processor's cooling requirements do not take into account the additional heat that will be produced or the rate-of-change of temperature that might occur when the processor is being overclocked. Now, this is obviously not going to anywhere near approach the levels that are produced if the Cores were being overclocked, but it can still potentially have an effect on the lifetime of your processor. Bottom line, if you are going to do things like this, the better the cooling solution, the happier the processor will be. Secondly, as clock speed increases, noise on the memory buses will also increase. If the additional noise approaches certain thresholds, memory read and write errors can occur. Now, a properly-designed motherboard, if they are interested in having it support these higher speeds, will attempt to account for this with better circuit isolation, better bus termination (to prevent reflection, etc.), better quality components (that generate less noise), etc. Whether this is sufficient for the memory speed that you want to use is something that you will need to establish. Read your motherboard's documentation. If it doesn't say, challenge your (potential) manufacturer to identify it for you.
Hope this helps,