Weird re-Toasting phenomena

[vix]

I created a normal video dvd a few months ago with clips I collected from the web, I toasted it (toast 6 titanium) as an NTSC dvd and it played fine.
Tonight I'm trying to reburn a dvd using selected VOB files from the video_ts folder, only files from the previous cd, no additional files, but toast is giving me a message saying that I cannot have both PAL and NTSC clips on the same disc!!!

how is it that if the dvd was previously all NTSC, it is now saying that one, or some of the clips on it are PAL??

[BsMx]

is very weird actually, cause you say it all was NTSC and then Toast says it's PAL

check your files with MPEG Streamclip, just to make sure nothing happened