Theme problem

By adoi

Hello,

I am trying to add theme to my 

clean_simple or theme_community in my new elgg installation.


But i am stuck in a problem. when i uploaded the theme in the mod directory. and enabled the theme_community all pages got distorted with default pages in the downside. 

But strange thing was when i disabled the theme. theme got implemented on my site. 

Although all pages are working fine. Please tell the reason of error.  Also how to enable the default theme of elgg.

Thanks in advance.