Ok, I have this movie in some weird frame rate (23.975). When I put it into AVI2SVCD, it said it will change the frame rate to the correct one. Then I thought it must change the audio rate too. After AVI2SVCD did the extraction and conversion, I noticed the command line for BeSweet included the frame rate coversion for audio [-ota (-r 23975 23976)]. So, I thought good, I don't have to worry about it. Also, in the Avisynth script, it stated it will change the frame rate to 23.976. After a while, AVI2SVCD finished and I played the muxed file, the audio is way out of sync.
So, what's the problem?