Xinha requires Images, and Javascript files to be loaded, which should be present in your public directory. Myself, I just uploaded xinha to my public folder and let my RewriteRules allow correct filenames to passthrough and not be bootstrapped, another way around it is to just turn the rewrite engine off with an htaccess in the xinha folder.

We could really use a helper or plugin or something for an Rich Text Editor for the ZendFramework, because i cannot stand the mess that is incorporating things like xinha.