Cd-rom drives?

how come my backups will read in some cd-rom drives but not others. also why do my back-ups read in pretty much all dvd drives? I use lite-on 40125s w/cloneCD. I guess i am looking for a technical answer. (acer cd-rom drives never seem to read safedisc back-ups)

I am not making copies I am just trying out old hardware.

Could depend on various little things…

Perhaps your reader is too old and the media is MMC3 (instead of 2 or 1) , or the lens is broken/damaged/scratched.

The CD you made could also contain more than 1 session , have a bad reflection layer , etc…

so its possible that the drive that wont read might read if i try a different media? i am pretty sure there is nothing mechanical wrong. i just thought cheap-o drives may be lacking something that better brand drives are not.