Back to the original problem... After a lot more research I've discovered that there is definitely something wrong with your IFO patching code. Based on the unofficial DVD specification guide the "Start sector of VTSM_VOBS" should always be set to 0 if the VTS_1_0.VOB file is not present. However in the sample folders I sent you the VTS_1_0.VOB did not exists yet StarBurn set the "Start sector of VTSM_VOBS" value to 6. Nero correctly set it to 0 as required by the specification.
Quote:
Byte offset 192, Start sector of VTSM_VOBS
If the Video Title Set (VTS) contains a root menu or other predefined VTS menus (angle,
audio, chapter, or sub-picture menu) the file VTS_nn_0.VOB will be present, where nn is
the title set number. This value helps the DVD player locate the file VTS_nn_0.VOB on
the disc quickly. The value is the last sector of VTSI + 1 (the file size of VTS_nn_0.IFO
in sectors + 1). If the VTS_nn_0.VOB file is not present, this value is set to 0.
I've tried StarBurn on several other DVD projects as well, which also do not contain a menu and as such do not have a VTS_1_0.VOB file, and SB always sets the "Start sector of VTSM_VOBS" value to 6 instead of 0 like it should.
Hopefully that will help lead you to the bug and allow you to fix it.
Dan