I have 12.16 before with the same problem. So i tried uninstalling it completely. I even deleted the opera folder in
roaming directory and tried installing again Same Problem nothing happened. Then while i was in 12.16 it upgraded to 12.7 itself. But still the same problem.
I found this same problem Here :
http://forums.pcbsd.org/archive/index.php/t-19190.html (I read on some sites that this solution worked for them)
But it was in linux and they sucessfully resolved it. So, i edited their code in my operaprefs.ini and
nothing changed still stuck with those black sub-menu.
I couldn't find any solution of this problem. Somebody please help.