This also happens with Woothemes main Canvas theme too.
Bit more info, the menu on pages where photoswipe has replaced the lightbox, the menu is working fine. On all other pages though the menu doesn't work.
This also happens on a desktop browser if I set it to always replace and make the window smaller to get the "mobile menu". The home page the menu doesn't work, on the post with a gallery the menu does work.
http://unseeingeye.com/test/ (I may do more tinkering in the mean time)
There is also another thread with the same issue http://wordpress.org/support/topic/mobile-iphone-menu-eaten-when-using-photoswipe-for-nextgen-plugin
Given that it works on the post with a gallery but not the rest I would think it was due to the plugin rather than the theme. I would be surprised if a large theme company like Woothemes who wrote the wordpress menu system would be doing something non standard too.
I'm happy to help out in any way I can, though I'm not much use with the inner workings code wise.