Its doing it to me too.
The default page for Mambo (when you access it via domain name only) is the first item on the main menu. This is specific and it will only look for that item (main menu - first item). It looks for the item with the lowest ordering number in the menuitems table where the menutype field is "mainmenu", parent is"0" and published = "1".
Here's the query (replace "#__menu" with "mos_menu" in the table reference to understand it):
PHP Code:
$query = "SELECT id, link"
. "\n FROM #__menu"
. "\n WHERE menutype='mainmenu' AND published='1'"
. "\n ORDER BY parent, ordering LIMIT 1"
;
It looks like the first item on your main menu is a seperator line, which may be causing this problem. If you want the front page component to be the default item, it needs to be the first item on the Main Menu. If the menu at the left of your site is the main menu, it needs to be the first item there.
You could setup a menu (call it anything other than main menu) to dsiplay those items, then use the main menu to display the option to the lower right of your site that includes the front page component, and it should do what you want it to.