LG DR4912 DVD recorder + r media

I've just bought the LG Dr 4912 which appears to be great value at £149.BUT I am unable to play +r disc's which have been copied using SonyDVD RW D56A,( +RW's play ok). I get the message "unknown disc".I am using Clone DVD2 2.4.5.4 and ANY DVD 4.0.4.1.

Previously copied discs using a previous laptop which are copied onto + r's work fine.All the copies work in my Pioneer 575A.

Any suggestions ?

Cheers