Background image for the currently selected menu item (RTL) is not displayed

Happens on right-to-left (RTL) sites on unix machines.

Issue caused by this css rule:
mpFREE/css/light-blue-skin-rtl.css:
#mainmenu ul.menu li a.active {
background-image:url(../images/mainmenu-active-bg-rtl.png);
background-position:right bottom;
}

Since the background image is saved as "mainmenu-active-bg-RTL.png" (notice the upper case RTL).
Same happens for blue-skin-rtl.css skin.

Fix should be change the css or rename the image.

This may not reconstruct on Windows machines.

Cheers.