ABP icon missing in toolbar and Customize

I can no longer see an Adblock Plus icon on my toolbar nor is it listed in the Customize Toolbar feature. Adblock extension is listed as enabled in the Add-ons tab. Have tried disabling/re-enabling, and re-installing the extension. No luck. Please advise how to re-enable the icon.
Windows 8
Firefox 22.0
Windows 8
Firefox 22.0