BD Playback problem

[Munstrom]

Hi all, new user here. I've only recently taken advantage of my blu-ray disc drive on my pc, set up is as follows.
Vista premium 64bit
Intel Core2 Quad CPU Q6600 @ 2.40GHz
4gbs of 800 mhz ram
2 512 mb 9800 gtx+ in sli

and an lg ggc-h20l blu-ray/hdddvd combo drive.

Until today I've had to use powerdvd 7.3 to play my blu-rays, no other playback software has worked including corel windvd 9 plus and powerdvd 8 ultra. I'm only using the deluxe version of 7.3 as upgrading it into ultra for some reason means it will cease playback and return an unsupported disc in drive E: error.
Anyway today I bought the batman begins/dark knight boxset blu-ray and went to play it, It got as far as playing the warner bros intro on both batman begins and dark knight before going to a black screen of a spinning dvd ( I waited 15 minutes assuming it was just loading, nohing happened) I popped in the bonus content disc that comes with the dark knight which for some reason plays fully. All my other blu-rays play as well.
Is it possible that the discs are defective or is it more likely in relation to the version of software I'm using to try to play them?