Probably the same issue with a different manifestation, but I've got some tools pinned to the bottom of the editor window, and they spontaneously multiplied when switching workspaces. Also, tools that I have pinned to the left side of the editor window were duplicated in the bottom. I didn't notice until I went to change tools, so I don't know exactly what caused the growth, but it was definitely during a switch among workspaces. I've only seen this on the Linux version, not the Mac version.
-Tim