I thought all DVDs should be stored at 480i or 587i on disc? Otherwise the DVD player would have to re-interlace to produce a signal for non-progressive video connections i.e. scart. Cheap DVD players will no doubt make a huge mess of this, or the DVD just wont work at all on a non-progressive scan player.
I've got a video processor (DVDO EDGE) that will reprocess progressive material to extract the original interlaced fields, and then deinterlace properly. Works a treat on the Noshame discs.
You should have no problem with them providing you have something with good deinterlacing on it.
I've since upgraded to a HD LCD TV, and they look fine via SCART but rubbish via HDMI
That's likely because scart will be sending out 480i and the HDMI will be sending out a poorly deinterlaced 480p signal. If you can force 480i/576i out of your DVD player via HDMI, that would fix the problem.
If anyone has Sky HD and wants to see poor deinterlacing in action... go to the standard definition Bloomberg news channel and witness all the combing and stuttering caused by poor deinterlacing in the Sky HD boxes. Same effect.