sorry, didn't get that from the first post.
I was referring the the cable select jumper on the hard drive. all (i think) IDE devices have a jumper where your options are master, slave, and cable select. I was thinking maybe if you were putting together a pc using many old parts, the hard drive may have the jumper set to slave instead of master.
"intermittently" ---- I would guess a bad cable. Its happened to me and believe me it was the last place I looked.
I couldn't tell from the pic's I found online, does your mobo have 2 ide channels or just one? Never mind, it does have 2, try the other IDE plugin on the mobo.