MB,

I have noticed many times that following memory or sometimes FSB changes i have to shut the PSU down completely...simply a reboot will not work. and most of the time once the PSU is turned back on and the system is powered up, it will not POST, just hangs on a black screen. give it a hard reset and everything works fine.

in other news, finally got everything working again after 1521. seems that mch voltage prior to 1521 is not sufficient for 1521, bumped it up and all is good.

will post details later

sean