Could it be a copyright issue? Some Sony players refuse to play copied / home-made disks!
pipo
November 2011
Sounds like the lasers on both are nearly dead, they don't last forever and get weaker and weaker over time. Once they go out of tollerance they will start to skip or fail to 'toc' (read the disc) and replacement becomes necessary.
Trap
January 2009
I can answer this question...
Sony CD won't play some cds and plays others. Has been cleaned?