odd hd problem

[Maezr]

my setup:

primary ide channel has primary hd and dvd burner

secondary ide channel has had one hard drive for a long time. I tried to add another one of my old ones today, but I couldn't get it to work.

both drives from the secondary work fine if they're by themselves and set to master. when one is set to slave, both are no longer detected.

any idea why I could be getting this?

 

[Nohr]

First thing I'd try is another IDE cable.