Message behaviour Accessibility plug-in is not consistent within Hippo CMS

[Jantine]

Browser: Firefox 30.0
CMS: Hippo
Plug-in combined with: CKEditor
Situation: Quail plug-in does show error message in pop-up, but seemingly at random. Sometimes the pop-up is empty, even when the situation in the content window has not been altered. The screenshots show the result of a first click on a dotted piece of content (with message). When that pop-up had been closed, I clicked again and saw an empty pop-up.
Expected situation: Quail plug-in always shows content in pop-up message if there is something to report.