Help!! The P4v8x-x don't work with atapi device now!!! Why??

I have now the pc of my friends, with a asus p4v8x-x motherboard... It
work fine if ther'is the hard disk master in first ide channel as
master, but if i connect one or two cdrom device in the second ide
channel, or one in first channel as slave, the pc is very very slow
at the boot or fail the boot or is freeze in winxp, or/and dont
appear the cdrom units in win xp....
I have tried all, to change cdrom units, power switch, hard disk,
cable, restore default values in the bios... nothing. This problem is
borned two weeks ago, because in the past all the system worked
fine.... is possible that ther'is a hardware fall in the
notherboard??!!