SPD mis spec?

I'm wondering how my memory could have become 3-3-3-8 instead of the spec'd 2-3-3-6 by SPD. When I built this system I neglected to check the memory timings. So, Until today my system has been running at 3-3-3-8 timings...
What could have caused this?

Boards don't always read the SPD's properly. Some ram companies also set SPD timings a bit looser than the stock timings to make sure the ram will boot on all systems (we do this). One example that comes to mind is with DDR2 right now. Many boards can't boot with ram that has 3-2-2- or 4-2-2 timings since the board/bios makers were not expecting DDR2 to have timings so low

Memory is DDR400, corsair. And its a good motherboard. It seems silly too me that companies would program SPD higher than they spec them at. I could understand if it was the 2.5-3-3-<somethign> thats nessacary for amd boards, but 3-3-3-8? Meh, learn new stuff every day.