Help with DropBox folder action for OmniFocus

I have a dictating app called DropVox that uploads voice memos to my DropBox.

I want an AppleScript folder action to creat an inbox item to tell me that a voice memo has arrived with a date and time stamp.

Here is the script I used as a Folder Action:

on adding folder items to this_folder after receiving these_items
	tell application "OmniFocus"
		set uploadDate to (current date)
		set file_name to "DropVox - New Item Added " & uploadDate
		tell default document
			set NewTask to make new inbox task with properties {name:file_name}
		end tell
	end tell
end adding folder items to

It works, but when a single voice memo is added to the folder, it creates multiple inbox items, each a few seconds apart. It’s acting like the folder is being added to repeatedly.

I tried using Hazel instead, but I couldn’t manage to configure the script in a way that it liked. It just kept giving a “failed script” error message.

Thanks in advance for the help.