Cloning cd's from lite-on 486s to 52x combo

I don’t think this has anything to do with the hardware, (I’ve even changed cd disc brands) but… I’ve been burning software onto cd’s for a couple of years (always using Nero), maybe cloned one or two cd’s at most… but now I’m into cloning about 20 cd’s. Nero totally fails on a cd copy (copies half the cd and then tells me there was an error. The cd comes out half-copied.

With Alcohol 120%, I get total failure although it doesn’t damage the cd.

I thought, "hey, you’re cloning cd’s, use “Clone CD”. So I downloaded it and I’m using it and it works.

It is taking me roughly twenty (20) minutes per CD. Usually I burn a software CD in 3 minutes or so with the 52X Lite-On combo burner. So err… is this normal? What is “on the fly”, which I am not using, and might be faster? but less safe?