You can examine the .wmv file with Gspot video utility or MediaInfo to find the specifications of the file if you want to know the framerate…I don’t use ConvertX, so I don’t know what kind of fine control there is available to adjust encoding settings.
To fix the dvd you have now may or may not be possible. One tool that sometimes works with audio sync problems is the QuickStream Fix tool in VideoReDo. This is not a free program, but there is a fully functional trial available for download. VideoReDo TV Suite should be able to import and export a complete dvd.