If the site you are trying to visit is not coded properly for FF, no that fix will not work. If some of your settings in FF are causing the problem, yes it may work. If the site is not properly coded, the only fix is Coral IE Tab or IE Tab2.
I have not used IE Tab2; but I do use Coral IE Tab frequently. What these extensions do is to switch the rendering engine. The rendering engine is what displays the web page. Coral IE Tab causes FF to use the IE rendering engine to display the page. Thus the page display properly. Some websites are designed for the IE rendering engine and do not make allowances for any other rendering engine.
I would suggest you try this before resetting your FF settings to default.