I had to disable this addon, because it breaks websites too oftenly without any indication of what might be the cause.

In part, it's Firefox's fault for not putting the name of an addon in a javascript file when using the debugger on a website, and running into a addon file.

Mostly though, this addon seems to be unreliable. I don't know why this keeps happening, and I'm not going to assume inherently bad design, but the fact of the matter is that I can't use Firefox in a reliable manner with this addon enabled. The fact that it breaks websites in ways that have seemingly nothing to do with cleaning up a url or two, is unacceptable.

This addon needs to undergo some serious fundamental changes to be (more) reliable. If that day doesn't arrive soon, I might consider totally removing this addon and reporting it for malbehaviour.