Strange One... There shoudn't be any difference in regards to reading the data on both Disc's "TDK". They were both recorded one after another using the same Yamaha CRW-F1 Writer.

As a quick test, put it into a DVD player or your PC, there is of course a outside chance that the CD has been damaged in transit, anyway glad you like the Music, hang on to the disc's, and prehaps you can try them on someone elses set up, then ship them on to someone else to try!