It is possible due to overriding CSS rule for menu-help with more specific one.
Try to change
Code:
.menu-help .title-bar img.icon { background: url(images/dingbats_help.gif) no-repeat; }
to
Code:
#left-bar .menu-help .title-bar img.icon { background: url(images/dingbats_help.gif) no-repeat; }