same issue here... rev A1 with 1.08 update and no more HDMI detection. Also about 1 month ago the dsm-510 stopped storing wrireless information and continues to revert into setup upon boot (even after I config the wireless, it restarts to set the config, but always comes back as if the setup didn't stick.)
among the many other issues, I was having good luck using WMP11 streaming to the device wirelessly but now, no matter what version I either can't get HDMI or I can't get connectivity.
Why do we have to stick with an older update (v1.02) when there are so many fixes/enhancements 1.03-1.08... I mean, with only 2 video outs you would think HDMI would be priority.