I got the same "Unable to Install Canola2" error this morning but it dissapeared from the installable applications list and appears as though it did install.

After a "real" restart without the power plugged in, I tried starting it again but I have the same "Loading Canola2" message then nothing happens.

You mentioned something about doing a "full removal" I think, with the command line? Pardon me for my noobness but I'm really not experienced with the X Terminal (I think thats what I need to use right?) how do I go about doing this?