Administration icon not follow user theme

Hello, I have created a new theme for moodle, but I do not succeed to replace the admintree's icons.

I have followed the instructions in the documentation:

• I have activated the variable one $theme->custompix=true in config.php ;
• I have copied all images of moodle in mytheme/pix ;
• I have copied the /block folder in mine mytheme/pix ;

If someone has already resolved prolbema it I pray of give news to me.

thanks for your interest