Click Add to Favourite get this small window for adding You see: Folder: drop-down list, containing: Bookmarks Toolbar Bookmarks Menu Unsorted Bookmarks

Choose...

Folder_one Folder_two Folder_three

You click Choose...

Now, the drop-down list looks like

Bookmarks Toolbar Bookmarks Menu Unsorted Bookmarks

Folder_one Folder_two Folder_three

and you save to Unsorted Bookmarks

But, in my Firefox, after clicking "Choose..." a large rectangle with folder tree appears immediately under the drop-down list, separately from it. If you cannot see it at all, you have a problem. It can be caused:

by userChrome.css (rename it to userChrome_renamed.css)

by Firefox theme (try using default theme: Tools->Addons->Themes)

by an extension (try disabling them all or one-by-one: Tools->Addons->Extensions)

Try running Firefox in Safe Mode (there should be a shortcut Start->Programs->Mozilla Firefox->Mozilla Firefox(Safe Mode))

P.S. Update Java, please. You use version 6.07, while the most recent is 6.20.

Be sure you have selected "Bookmarks Menu", Click on "Choose" and you can: -use the slider, or -the up and down arrows at the top and bottom of the slider to get to the folder.

See attachment at the bottom of this post.

Does this help?