Audio and video dont match despite being the same length

[DaneClark]

I used audacity to fix some audio issues with the video I'm working on, then opened the video on virtualdub and selected "audio from other file." When I play the video in virtualdub the audio and video get out of sync like it would if they were playing at different speeds, and have checked everything and there is absolutely no reason why the shouldn't be the same speed, the video file I have opened in virtualdub and the audio file I have opened in audacity are both shown as being the exact same length right down to the millisecond, someone please help me

[jagabo]

Variable frame rate source?

[johns0]

Being the same length doesn't mean they will be in sync,were they in sync to begin with?

[DaneClark]

Being the same length doesn't mean they will be in sync,were they in sync to begin with?

Yes they were in sync to begin with

[ProWo]

post a mediainfo report (text mode) of the original video (before you changed the audio track) here.

[Selur]

probably vfr or a delay being not taken into acount during muxing,..

[poisondeathray]

what operations did "fix some audio issues" include ?