Why some mods are not working in the customize themes?

[Seo-luntan]

   Hello!

 My question is why some of the mods are working only in the Core theme, not in the customized themes?

P.S. For example in my SMF forum the H1 tags are out of order - if you want, have a look and give me some advices: http://www.seo-forum-seo-luntan.com

[scrotal]

If you pay attention to what it says for what is being changed when installing mods, you'll see it's modifying files in the default theme.  If you want the mods to work in customized themes, you'll have to make the same changes to the custom theme's files that were made by the mod's installer. 

[Seo-luntan]

 I see. Good advice! I can try it next time. Thank you!