MPEG 2 help

[biferi]

I have Movie Studio 8.0 and if I make an MPEG 2 File it plays ok.

Now I also have Next DVD Ripper Free and Actusoft Free DVD Ripper and wen I Ripped a DVD I always pick convert to MPEG 2.
And it works but wen I play the MPEG 2 file back a window comes up that tells me One Or More Pins are missing and you may not have the CODEC to play back the file??

This only happens wen I make an MPEG with Actusoft Free DVD Ripper and Next DVD Ripper if I make an MPEG 2 file with Movie Studio 8.0 it plays back ok????

I thought that the MPEG 2 CODEC for compresson was there for any program that would need it so if Movie Studio used it why is Actusoft Free DVD Ripper and Next DVD Ripper having problems???

Or is this not how it works??