Well... this method is only good for converting a single file on a single disc. Think of the horrible quality that would emmerge from 4 - 5 already heavily compressed DivX files, merged into a single, DVD movie... I wouldn't watch that.
As for the DVD menu's when converting from a DivX movie, I haven't researched on that, it is of no interest to me, it would have made things much more complicated.
Maybe you can improve my method to help more people with this issue.