SEF URL Problem in Joomla1.5

My joomla site url is: http://www.cessnatrader.com. I am using SEF URL for this site. The SEF URL is not working in the main menu(in top). But it is working fine for other places(other links, footer menu). I don't know what the problem is.开发者_StackOverflow I did all the things for enabling SEF URL in joomla. But it is not working in one place(main menu). What should I do?

Note: I am using "Mosets tree" component in this site.

Try removing all of your menu items and then add them again. One thing I've noticed when implementing SEF URLs in Joomla was that any link I created before I turned on SEF wouldn't be converted. Delete and rebuild the link from scratch.