Ulead VideoStudio 8 skips video

[D@rkmoon]

I¡¬ve got a weird problem with rendering a disc in VideoStudio 8.
I want to burn a disc with three different VideoStudio-Projects. So I added them in the make-a-disc window of the first clip, made the menus and so on... but in the preview it definitely skips the end of the second clip. ALWAYS at the same point regardless of the audio or videoclip and transition placed on this position (I replaced the clips there to test this). It always skips on the position 4:30 and jumps to the next project although the duration of the clip (even in the setting¡¬s window there) is actually 5:01. And no I didn¡¬t cut the project here. It¡¬s a stop for absolutely no reason. By the way if I open just the project where the strange behaviour appears, it previews everything correctly in the right length. Only in the disc preview and on the burned disc the end of the second projectfile is skipped. Changing the codecs has no effect, too.
Does anyone have any idea why VideoStudio has this problem? And how I can fix it without having to make the whole thing again?

Sincerely
Ferdinand