Currently Being ModeratedJun 14, 2013 10:32 AM (in response to GH)
That is the toggle for the bookmarks. If you are indeed synching through iCloud, that's probably why you have duplicates. It will take a while to sort out; this article may help:
Whether you use the suggested utility or clean up your duplicates manually will depend on how many you have and how much work you want to go through.