Don't use ThorUI myself but look in your mod UI directory and see if it includes a file called eq2ui_mainhud_skills.xml
If it does, delete that file and you will then start using the SOE default skills window instead (but retain the rest of ThorUI). If the UI mod is the problem that should fix it for ya.
...honor is a harder master than the law. It cannot compromise for less than 100 cents on the dollar and its debts never outlaw.
- Mark Twain, a Biography