I've noticed that recently the header and footer on our site are not being displayed correctly. They start off ok but after a few menu selections the footer disappears and the header is overwritten with the main menu background colour. Clearing the joomla cache rectifies it until a few more menu selections have been made. Some pages seem to be more prone to show the problem than others but I've not been able to determine any pattern to it. Has anybody else seen similar problems?
