My audio sync solution with converting MKV to DVD for Adzapper's movie downloads
First you need to download both
MKVtoolnix from

http://www.bunkus.org/videotools/mkvtoolnix/downloads.html

and

MKVExtractGUI from

http://coreforge.org/frs/?group_id=33&release_id=17

When you have them, you need to install MKVtoolnix.

Then open the MKVExtractGUI archive file and grab the files within.

Then you need to move those files to the folder your MKVtoolnix installed in and double click the MKVextractGUI.

This window should pop up.

Now click the button beside the input field and select the mkv file you want to extract the audio and video file from.

Now Open the file and wait a second or two till the tracks appear and check the ones you want hit extract. (The extracted files will appear where your mkv file is unless you change the extraction location)

Now exit the window and launch ConvertXtoDVD.

After you have done that, use the menu or the add video button.

You want to now adjust the Files of Type: to show All files.

Select the video file that was extracted.

When you open that file, since the file type isn't totally supported it will not automatically know the movie length, just hit automatic so it can find the movie length.

Expand the Titleset tree and right click on the audio (which should currently have 0 streams) and select to add audio.

Then select and open the audio you need for your movie

I will leave all the other video options up to your preference.
Now all you have to do is press the convert button.
If you wish to be able to see if your movie is really correctly synced before burning then get to the burning options.

And uncheck "Burn result to DVD" on the window that pops up.

You can now go to the vob files and view the movie and see if it came out right, you can look at the path of mine and see if yours goes to the same directory.

Don't worry though, you can still burn it to dvd, just go back to the ConvertXtoDVD program, and even if you closed it already, you can just go to the Action menu and click "Burn a project already converted".

Then select the folder where the vob files are located.

Then just go ahead and burn. That is pretty much all there is to it.