Merge MP4 with audio

[SoberWarlock]

I have converted a video that I edited using Vegas Pro 11 and rendered it as MP4 (specifically for web). Then re-encoded the video @ 60fps using this guide:

http://www.spirton.com/convert-videos-to-60fps

The only problem with this is the audio is not part of the video any more. I have tried using MP4Box to merge the audio and video and my video player does recognize it perfectly with no errors but it's just mute as if the audio is not there. Is the 60 fps conversion causing the problem?

[SoberWarlock]

I actually fixed the problem. When using MP4Box make sure the external audio has no tags. I used Foobar2000 to remove all tags and renamed the file to something shorter such as "sound.mp3".

After doing that I muxed the 60fps video and mp3 together and output was successful.

Take note guys. This program saved my life.