I know I'm not using Studio but rather Ulead Movie Factory 4.0 (including update patch) and it appears I'm having similar problems.
I convert my video files to DVD format using WinAVI as it works a TREAT! Usually I would import my files into Ulead Movie Factory via the CREATE DVD FROM DVD DISC/FILES and make a nice menu for them etc and hey presto it's done.
It works for most files but sometimes it just simply won't import them which is frustrating because I've used EXACTLY the same process so why on earth won't it accept these ones??
I thought I'd try the FixVTS which seemed like a great solution but unfortunately I got the exact same error. For anyone using Movie Factory here is a screenshot of the error I get when trying to import my DVD files.
It's a shame because it's so easy to use and the best so far for working with already encoded DVD files and I would love a solution to this error.