Sounds like a positioning error or possibly z-indexing.
Are you using relative or absolute positioning of an
element/s that you have inadvertently placed on top of your spry
menu? Or, have you assigned z-indexing incorrectly? If none of
these apply check that the menu's containing div is stacking
correctly within the document flow. Try deconstructing the page to
the point where the menus works correctly. Failing all of that post
your code here (but not the Spry js library).