If neither is installed correctly then why does it properly work via the command line?

Here is a JPEG created via the command line: (ffmpeg -i actionav01.avi -f image2 -vcodec mjpeg menu%d.jpg)

http://movietype.com/samples/menu50.jpg

Here is a movie encoded: (ffmpeg -i actionav01.avi -s cif -f m4v -vcodec mpeg4 MVI_0000video.m4v)

http://movietype.com/samples/MVI_0000video.m4v

Which works and opens fine in VLC. So if these things are not installed correctly why do they work?