It shouldn't matter if it is set to master or slave, but most would say master given the choice.
franklin97355 has a point about reader and writer not being on the same IDE channel, but this is not really an issue now with the advent of "Burn Proof" or similar technology, buffer underuns are a thing of the past, gone are the days of 1 in 3 coasters, it is quite save to put reader and writer together, besides, the alternative is putting a rom device with the hard drive, which can also have undesireable consequences.
Martin Replying helps further our knowledge, without comment leaves us wondering.