colorKey 2.0.0 for Maya (maya script)

Dear sir, excellent plugin! I love using it to highlight my keys but my problem is, it messes with my maya installation and I can't turn it off.
I'm using Maya 2015 x64 SP3. In my last project I used the plugin to set keys on a character. Then I removed every color key by selecting all controllers and pressing "REMOVE" from the ColorKey GUI. All colored keys dissappeared on the graph editor and I closed the GUI by hitting 'x'.
However after that, when I tried to key a controller  by hitting 's' the Colored Key channel reappeared in the graph editor.
It looked like the plugin was connected to this scene.

So I quit maya, deleted the plugin and opened a new scene. I just made a polygon and hit "s". and in return i'm getting this error:
# Error: line 1: name 'cKUI' is not defined
# Traceback (most recent call last):
#   File "<maya console>", line 1, in <module>
# NameError: name 'cKUI' is not defined #

seems like the program is trying to call the colorKey UI every time I hit 's' to key something...
Any idea what could be causing this? What can I do to get rid of this error besides fresh installation?
Thank you for any help!