There are 2 more of the exact same appearing icon or whatever that only have 'help' remove, about and lock or move. I am using Mint 17 MATE and the process is a bit different to get the Add to panel list, but right clicking on a nearly invisible icon of 4 or so horizontal dash marks on the panel that look just like the notification area icon but this opens up the has 'preferences' in the list with 'lock','move' and those. I happened across this Aug3,'14, for my Fox Fire always disappearing when minimized and ending up with lots of extra open browser windows from clicking on the icon thinking it was how to open /maximize to the screen at prior size-not full screen.
