hi, think there is some informatione about the issue in these blogposts: http://labs.episerver.com/en/Blogs/Ted-Nyberg/Tags/Search-Server/

its for 2008 but will probably work with 2010 as well. :)

Files that are linked in content will be found. For PDF files content to be indexed you need to follow this guide:

http://www.mossgurus.com/adnan/Lists/Posts/Post.aspx?ID=40

You can make the Search Server bot login to your site or sniff the user agent and output all files of a VPP-path just for the bot if you want to make sure all files are indexed.

I haven't found a good way to filter file hits by permission in the search results when EPiSite isn't using Windows Authentication. Looks like we'll have to filter in the EPi-application after retreiving the results.