If you have deleted the cache file and have this problem still there might be a problem with the preset that you have crafted or a corruption of your configuration folder. If the problem is the configuration folder you will need to rename it to undo the corruption, here is a link to the steps you can take for this.
showpost.php?p=12293&postcount=2
If the problem is with the preset then you would experience this problem regardless of the config folder. If you have any further trouble with this please post back with an export of the menu preset you have crafted and include some info on the steps that you took to create it so we can look into this further with you.
