Problem playing Blu-ray discs on 2 UK machines

[DH44]

Hi, I have a Sony S300 and a Pannasonic BD35 and on certain discs they both suddenly stop playing and restart from the begining of the disc, but then play okay (I've rewatched the movies it's about 6 or 7 now of a largish collection and they all play the 2nd time with no trouble so it dosen't look lile it's a faulty disc prob, all firmwares on both machines have always been up to date(using a CD-R) and none are conected to the internet. I've tried changing HDMI cables x 3 times all are top of the range, but the problem still seems to be acurring, the last movies to do this were State of Play and just today Tears of the Sun. (UK Blu-rays) Iv'e got both players set on the original manufactered settings and i'm not currently connected to an amp just my LG 1080p 42" TV.

Has anyone else suffered / suffering from this problem? Any solutions?

Any help would be apreciated, thanks DH.