copying on the fly

[bersjam]

When trying to copy "on the fly" my system warned me about the fact that both my source and destination cd are on the same IDE-bus.
The shop told me that this configuration is the best one but this means I'm not able to copy on the fly with any program I own(Nero, Cdrwin and Clonecd).
What should I do: make use of another program like the shop told me or put the writer and the other cd on different IDE-busses?