Simple: if your source is anamorphic you have to set "source_anamorphic=true", else pout "source_anamorphic=false".
If you plan to watch the KVCD on a 4:3 tv set, put "dest_anamorphic=false". If your tv set is widescreen use "dest_anamorphic=true"
The default are true for source and false for dest (as almost all DVD are anamorphic and most poeple watch the KCVD on a 4:3 TV).
No if you want an explnation of anamorphic term, I just wrote a very long post about it in the french forum and I'm too lazy to translate it