On the second computer that wouldn't write to the InCD Disc I'm getting the following message when I try and read from it:
You are currently trying to read a disc in the Mt. Rainier format (CD-MRW). You are seeing this message, instead of the contents of the disc, because your system currently does not support the CD-MRW format.
I have reinstalled InCD and updated it to the same version.
It's starting to really annoy me. There's no reason that I can think of for it not working!