I have not been able to reproduce the multiple rings bug yet.
Some other small glitches I have encountered:
I seem to be experiences a kind of double execution on some commands, such as scrolling through and selecting a written message, throwing a spear. It does not happen with movement, just menu options. In other words it is like accidentally clicking twice on enter or scroll.
Last couple of days the game seems to get stuck on Loading (something). Maybe a server issue?