Need to change category name for custom post

I had to switch to multisite for many of these plugins to work, and now that I have there are problems.

This page:

http://dvdreleasesandnews.com/trailers/

Is a custom post page, and it has this sidebar (see picture).

When I click on one of the trailer links, it takes you to a 404 error page because the URL now has "blog" on all category pages thanks to multisite.

Here is the 400 error page it takes you to:

http://dvdreleasesandnews.com/trailer_category/coming-soon

(this page used to be right before multisite was installed)

And here is the page that it is supposed to be taking you to:

http://dvdreleasesandnews.com/blog/trailer_category/coming-soon/

Someone please help with this error.