Widget Icons (CSS question)

[acabmg]

hey folks! Foreword: the grammar of this statement is likely to be bad, because I used a translator.


I want to hide the widget icons and try with the following code:

.cms_widget_header h3 img {
display: none;
}

if I use this in the firebug, this works fine - but when it goes live to work, nothing. : (
can you tell me what's the problem?

greetz from germany!