[Plugin: Image slider with description] Custom Menu disappears when Plugin In Use

I’ve installed this plug in and set up my images. Then I created a page for the gallery and used the shortcode to insert the gallery.

Unfortunately, my gallery shows up beautifully, but my custom menu no longer appears. I’m guessing there is a style conflict maybe?

Page is here if you’d like to have a look – menu should appear in the green bar across the top.

http://www.memorymosaics.ca/wordpress/gallery/

http://wordpress.org/extend/plugins/image-slider-with-description/