No sequence header on two vobs after authoring in Encore CS3

[Killer3737]

Ok here is exactly what i've done:

1) Decrypted a DVD made on a standalone recorder using IFO mode of DVD Decrypter to one large .m2v file and .ac3 file.
2) I wanted to reauthor the DVD in Encore, but the video was 704x576, which Encore usually re-encodes, which i don't want.
3) I therefore did a trick i usually do, used DVDPatcher to patch the M2V to 720x576. This adds a green bar of 16 pixels to the side.
4) I then authored in Adobe Encore CS3 as usual, and it doesn't re-encode.
5) I now have my output VIDEO_TS folder, which has 4 .VOB files, as the size is ~3.6GB. I then take the .VOB file back to DVD Patcher to patch them back to 704 pixels. This works fine with the first two VOBs. However, when i try to add VTS_01_3.VOB and VTS_01_4.VOB, DVDPatcher says "No Sequence Header Found" and tells me to select a valid MPEG2 file.

Now i've used this patching/authoring/patching method many times before without a problem, and the first two VOBs work fine here, so what could the issue be with the second two, and could it be fixed?

Thanks
Simon

[Killer3737]

Nobody any ideas? Would ripping the disc as a multiplexed VOB and running it through something like quickstream fix in VideoReDo help?