<< If they are on the same IDE channel, the data flow can interfere with itself.
A work around for that with ECDC is to click on the Advanced button, and direct the data to copied to your HDD first. Then the new CD is copied from the HDD and not the CD. It is slower, but surer, and is the original poor man's "burn proofing." >>
You can also just use your burner as source and destination. I have had 1 so far that did not work, so I used clonecd. It was in no way protected either!