I've had that problem too. Is it a CD/R or a RW? I couldn't read CD/RW on another computer but could on my own. UDF reader sorted it I think, but have you tried reading it in the RW drive ie the one that wrote it? or just in the ROM drive?
Lastly, if it's a new install, you may need to install adaptec again on the new computer before you can read the old stuff.