Just checked the cover and the disks are region 2, from a well know TV company in the UK and purchased on a large online retailer. In the 'TV player' it gives an error message of 'wrong disc' and on one laptop nothing at all it just whirrs and clicks and then gets spat out automatically. On the 2nd laptop it gets accepted and plays flawlessly......
If everything else plays OK in your TV player (which is really what the discs are designed for), I would try the suspect discs in a couple more machines - try friends or even go into a shop that stocks the set and ask them to test them. If they don't work flawlessly there, send 'em back. If the discs are fine in other machines it sounds like your player is, like all of us, getting older and crotchetier!