Do you have that problem when running in the Firefox SafeMode?
http://support.mozilla.com/en-US/kb/Safe+Mode
Don't select anything right now, just use "Continue in SafeMode."

When in Safe Mode...

• The status of plug-ins is not affected.
• Custom preferences are not affected.
• All extensions are disabled.
• The default theme is used, without a persona.
• userChrome.css and userContent.css are ignored.
• The default toolbar layout is used.
• The JIT Javascript compiler is disabled.
• Hardware acceleration is disabled.

If not, see this:
https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fi...

Still occurs using safe mode.

Could you describe your problem with more details?

Where are you dragging the bookmarks?

Is this to organize them or are you tying to move a link the the Bookmarks Toolbar to bookmark a web site?

Make sure that toolbars like the "Navigation Toolbar" and the "Bookmarks Toolbar" are visible:

• Firefox menu button > Options
• View > Toolbars (press F10 to display a hidden menu bar)

Open the Customize window to set which toolbar items to display:

• Firefox menu button > Options
• View > Toolbars (press F10 to display the menu bar)
• Right-click empty toolbar area

• check that "Bookmarks Toolbar items" is on the Bookmarks Toolbar
• If the "Bookmarks Toolbar items" is not on the Bookmarks Toolbar then drag it back from the toolbar palette in the customize window to the Bookmarks Toolbar

• if missing items are in the toolbar palette then drag them back from the Customize window on the toolbar
• if you do not see an item on a toolbar and in the toolbar palette then click the "Restore Default Set" button to restore the default toolbar set up

• https://support.mozilla.org/kb/How+to+customize+the+toolbar
• https://support.mozilla.org/kb/Back+and+forward+or+other+toolbar+items+are+missing

And it's working today. Just like that. Strange. Thank you for your help and I will keep the information should things screw up again.

It only occurs when I sort the bookmarks by name first, then try to drag and drop (in this case - in to a folder).

If I open the bookmarks window without sorting after name first, drag and drop works.

Hi sabruland

Are you using the Views menu to show the bookmarks in a different sorting order or are you actually sorting the bookmarks via the right-click context menu?

If you use the Views then you only change the order in which bookmarks are displayed and in such a case drag and drop may not be working, especially with multiple items selected.