I'm trying to Convert a PAL DVD16:9 to NTSC 16:9, I've sucessfully converted the video but I'm having problems with the audio file.

I've been using BeSweet to convert the audio from Pal to NTSC but having problems, I load the AC3 file into BeSweet and select the output file name, in the presets I select PAL -> NTSC (25.000 to 23.976) etc and then hit the AC3 to AC3 button, then after about 5 mins I have the newly created AC3 file

I then load up DVDlab drag my .mpv and new AC3 file in there and compile DVD, after it has finished creating the dvd I then go to the directory and play one of the VOBs to see what the finished product is like and it is all ok(with audio). but when I burn the vobs to disk and try to play it on a standalone player there is no audio, also tried playing the disk in the PC with powerDVD and there is still no audio, what am I doing wrong? how come the vobs on the HD play with audio?