The Sitefinity skins uses different sprite because of the dots as you noticed. To make it use the sprite, that other skins are using, you could use the following CSS code in the head section og your document:
div.RadDock_Sitefinity table tr.rdTop td.rdCenter,
div.RadDock_Sitefinity table tr.rdTop td.rdCenter .rdTitleBar
background-position: 0 -27px;
Attached is HorizontalSprite.png
that should be used. That will fix the issue, but the dots will disappear.
the Telerik team