New owner of Philips DVDR 80

I have recently purchased one of the above and 99% of the time it records ok. Sometimes though once recording is complete it refuses to play the disc from the beginning instead jumping to anywhere between 1 and 3 minutes of the disc. I have tried the play whole option and it still jumps - any thoughts why?

thanks Steve

please has anyone idea on this as it is driving me nuts and I am going through discs fast!