First of all: many thanks for your add-on. I had been looking for something like this for a long time.
I have several computers and I installed History Submenus II in all of them, but only in one, my main PC (Windows 7 64 bit, Firefox 32.0.3), it works correctly: it shows all the pages visited in submenus as expected.
In the other computers, instead, it shows only a few random pages under submenus, pages I visited many days before. If I visit a new page, it doesn't appear under submenu. But all the pages I visited (included the new ones) are correctly displayed in Firefox history. I tried to delete the history, but new pages are still not showed under submenus.
By the way, Firefox in all my computers is configured exactly in the same manner (same addons, same settings...). I installed it in PCs with Linux and Windows XP, and initially I thought it didn't work just in Linux and Windows XP, but then I installed History Submenus II in another PC with Windows 7 64 bit and got always the same problem.
Is there anything I can try?
Thanks in advance!