Yeah do as MichealK says. And it is possible for him to have a motherboard with four ide ports. I have one ide drive labelled /dev/hdf on my third ide port.
My only question is have you done something drastic in linux recently? If for instance you recompiled a new kernel, that might do it. I had problems because default kernel installs dont usually include the proper support for the two extra ide ports on my motherboard. So if you have done a kernel compile and left out the proper support.... Otherwise I dont know