This is an old topic but this is an old but recurring problem.
After having been "forced to reboot" since around the time this thread was started I discovered that the offending window is the PM download window. I for one would click into that window, linked from the announcement email (forum subscription), download the update and then click the download file to update. All that is needed is for that web page to be closed but figuring it out took a couple years
I think it would be most helpful if Kirk and crew either renamed that window such that it does not trip the install test, filtered web windows from the test, or at the very least add some text to the "error message" to suggest closing any web pages related to CameraBits, including the download page. It will save a lot of grief.