This isn't a Mint issue, but a desktop environment/window manager issue. It's the DE/WM that handles the menu. Some desktops put it under Accessories or Other. E17 puts it under "Other."
In the meantime, you should be able start it from the command line with the command VirtualBox--at least that works in Mageia.
Last edited by frankbell; 02-22-2014 at 10:56 PM.