I think I have solved this problem, not completely though. again I removed
everything under /etc that belongs to baselayout, and re-emerge it, (I still
don't know what the hell had caused the problem!).  however, when I tried to
restore some of my startup scripts like "metalog, alsasound", gentoo
complains with message like this: "Could not *get dependency info* for XXX,
try to fix ..... please run depscan.sh .... " could not remember all words,
but depscan.sh seemed no use at all !

thanks.....

daniel