See http://www.ottawapatentagency.com
Using Safari and Google Chrome, click on the menu item 'Our Services', hover over 'more' and the submenu does not fly out. If you click on the other menu items (Home, Your Patent, Contact Us, more) hovering over 'more' will fly out the submenu.
The page 'Our Services' is the longest page of them all, so I think that the culprit is a length threshold of some kind (I may be wrong, though)
Using IE, hovering over 'more' flies out the submenu on every page, including the 'Our Services' page.
Anyone in this great forum can figure out the puzzle?
The problem lies with the illegal placement of an image on line 62 of your document.
Remove the image and apply appropriate style rules to the sidebar.