I am using responsive blog theme on my client's website and it is running well. However to remove the default message on front page "No front page content has been created yet", I am using CSS Injector.
I have added a rule
#first-time{ display: none; }
in css injector. It was working well with other themes on the same website but using it with responsive blog showing an exception error as:

Notice: Undefined index: rule_themes in css_injector_init() (line 53 of /home/manisha/public_html/sites/all/modules/css_injector/css_injector.module)

Can any tell me where I am going wrong.
Thanks!