Firefox 18.02 trouble on Bookmarks export and import

[Guest]

I don't know why but it's strange when I want to import my bookmarks from Bookmarks (Menu -> Bookmarks -> Show All Bookmarks->) I can't drop down a menu from Import and Backup menu... and after that all menu if they have a drop down menu I can't open... just open and close the drop down...

Please help...

Note...
If from the begining I press Ctrl+Shift+O to open the Show All Bookmarks... I can drop down the menu and anything is fine...