Menus require MouseOff and MoveOver Layers to operate from if there are rollover effects.
If you add one to a Pop-up layer, you need the same construction. Search Help for "layers":
Layer ordering in website documents

If your website document has mouseover effects, pop-up layers and perhaps even mouseover effects on those pop-up layers, there are some important rules you need to follow in terms of how you order the layers in your document.
Considering the layers in turn from background to foreground (which is working upwards in the Page & Layer Gallery), first you must have all the static layers. These are layers which are always visible and are not used as pop-ups. In most designs there will only be one – the "MouseOff" layer. But some designs may have several, in which case they must be the first layers in the layer stack.
Next comes the MouseOver layer, if there are mouseover effects on the static layer(s). This contains the mouseover states for all your mouseover buttons. This must be followed by the "MouseDown" layer, if you have mousedown effects on the static layer(s).
Next you may have a pop-up layer. If the objects on this pop-up layer have mouseover effects, then the next layer following the pop-up layer must be the layer holding those effects. It must have a name that begins with "MouseOver", E.g. "MouseOverPop-up1". And then if the pop-up layer also has mousedown effects, a layer whose name begins with "MouseDown" must follow containing those effects.
Then you can have another pop-up layer, followed again by any mouseover and mousedown layers for that pop-up layer. And so on - you can have as many pop-up layers as you like.
MouseDown pop-up n
MouseOver pop-up n
Pop-up layer n
...
MouseDown pop-up 1
MouseOver pop-up 1
Pop-up layer 1
MouseDown
MouseOver
Static layer n
...
Static layer 2
MouseOff


Note that you only need to be concerned with these ordering rules if you are building complex pages with multiple pop-up effects! If you are just using the template designs provided in the Designs Gallery, you should not have any problems with layer ordering.
Acorn

P.S. If is kinder not to use SHOUTY CAPITALS in the Thread Title.