Is it only not detected at cold bood or at warm boot (reset) as well ?
on cold bood its better
Do you enter HDD parameters in Bios setup or is it autodetected at every boot ?
autodetect
Do you hear some strang enoises from your HDD ?
sometimes
It's possible you HDD needs to0 long for self-initialization and Bios HDD detect skipped it
it ca be. i dont know