.vob to mpeg2 or avi conversion

I bought Flash DVD Ripper to convert a .vob file that is 13 minutes long to a MPEG2. The MPEG2 works fine at home but at the work PC it is much darker visually. I converted to an AVI and the picture is much narrower and thus distorted. Where can I get info that will help me understand what is going on. As you can see I am a novice.
thanks in advance

please try Alive DVD Ripper also
http://www.alivemedia.net/dvd-ripper/index.htm