On Mac OSX when converting to DivX, the file extension is
.divx. This does not appear in the default shared extensions of LW.
Whilst I can add this manually to the shared extensions, I believe that for mac users this should appear as one of the default shared extensions. So this is just a suggestion to add it to the 'default' shared extensions list for us mac users.
Being a 4 letter extension, I'm not sure how this would affect windows users & whether it would become truncated.

Or how it would appear for them ... unless they see it as something else.