I'm a complete and utter noob when it comes to any kind of mod or template editing. However...
I've been trying CSB on a test installation (3.4.2) and everything was working perfectly as long as I used the default (custom) board theme. As soon as I tried changing to any other theme, I received the following error:
Fatal error: Method customSidebarBlock does not exist in dp33_gsidebars_boardIndexTemplateSkinOverloader
I then remembered that another app I installed required an edit to the the templates Board Index>boardIndexTemplate and Forum View>forumIndexTemplate. So, I decided to copy these modifications over to the other themes, which fixed the problem for me. I'm not familiar with Topic Hover, but perhaps the problem you have is similar?
It's just a thought...
PS. Thanks to the author for this great mod :smile: