This is exactly what I was talking about in the previous post, but it's not about the parameter specifically, it's about the | that separates the parameter.
The change I posted fixes the issue here so I don't know what else to do for you. Keep in mind that the change is probably not immediate because the incorrect version is saved in your forum's post cache. You can always view an uncached version of an article by adding &redirect=no to the URL.
If you can reproduce the issue again here I will look at it again.