no autodetect of 2.1 gb board

despite a bios update which was done correctly a samsung 2.1 gb-hd is not autodected only on asus txp4-socket 7 mainboard. on a second board its working.
o second 1.6 gb-hd is ok. i have tried outr everything. the main problem could be the following: i cannot start the bootprocedure if i use the setup cmos default. i have to use bios cmos default plus changing c,a to a, c. asus ask to use setup default before and after flashing.
i use the right flash utility pflash2.exe
i have already the actual bios but when i flashed something strange happened: i could see my 2.1-drive in the autodetect-window for a short time without right size(0 instead). and it was detected a master und slave…! jumper is ok.
i have shortened the bios data(cleardata) too( 1-2 min.) maybe there is a virus inside?