I have implemented three menus on the page which are under menus called TopMenu, Mainmenu and Bottommenu (all Level 0). The TopMenu (Level 0)has 5 submenus(Level 1) which are displayed using
Snapsis:NavMenu id="Navtop" Level="0-2" Type="Hover" runat="server" IncludeTabs="Topmenu" ShowType="ChildrenOnly" Cachetabs="true"

The Level 1 submenus also have submenus which is where I need help.

The first four Level 1 menus show correctly and the Level 2 submenus work correctly. The last Level 1 submenu shows correctly BUT its submenus are the problem. It is one big long list of submenus that starts with the correct Level 2 submenu and then the Level 2 submenus from the previous Level 1 submenu and then it starts again with the Level 2 submenu for this Level 1 submenu.

The problem occurs on the last Level 1 menu item always. If you add more Level 1 menu items the problem moves to the last. The problem only occurs when logged in.

The version of CSS Navmenu is 3.4.1.

That is strange. It may be related to the ChildrenOnly show type.
Are you using that show type to keep it from showing the parent items?
If so, it may work better to use ShowType="Always" and then change the Level="0-2" to Level="1-2".

From the IncludeTabs="TopMenu" it looks like you are trying to ony include the children from on root parent item, is that correct?

Having it only occur when logged in confuses me though. You might want to leave caching off until you resolve the problems (CacheTabs="False").

The changes corrected the issue. Thanks