UTesting your forum I've tried the Thanks Toplist address and get an error:
Unable to find template "toplist_body.html" (looked into: /[...]/public_html/forum/styles/BBOOTS/template, /[...]/public_html/forum/styles/BBOOTS/theme, /[...]/public_html/forum/styles/all/template).
This means the extension is installed and active, but something is failing. I'm not really sure what is happening because it doesn't include extension path so you can test this steps:
1) Reupload the extension. Maybe there're some files missing
2) Copy following folder:
(use BBOOTS in caps)
You may get the functionality but probaby you will need to edit that template files to adapt to your template if this one doesn't follow phpBB Prosilver guidelines.