Adding Metadata to Flash Video
Many Flash video encoders, especially older or cheap/free encoders, do not add valid metadata to files. In some cases they do not add metadata at all, in others cases the metadata is incomplete or causes problems.
The best solution is to use an encoder that does add valid metadata, but for many people this is too expensive. If your budget prevents you from purchasing a good encoder, you can try using a free program to ad the metadata.
I believe there are various free programs which can add metadata — try a Google search and see what you find. I have not used any of these programs myself so please do your own due diligence.
A couple of programs I have been recommended: