That must be a bug with the new bios and the E8400 proc in the DS3L. I'm running a G0 Q6600 in my DS3L with the F8a bios with no problems. And before I dropped the Q6600 in it, I was running an E6750 with no problems too. The only funny thing I had happen was that after the upgrade and trying to overclock too far, I had problems with it booting at any overclocked speed, no matter what I set in bios. But clearing the cmos cured that problem and it's running my Q6600 at 3510 with no problems.
I've got the E8400 in the DS3L, and I have intermittent issues. The first time I booted the machine it started and shut down three times before running. Every once in a while, especially after changing BIOS settings I'll get it when it starts, shuts down, and starts again. I'm running F8a (which they've had out since last year). Hopefully they release a standard release for this good budget board.