Thanks for getting in touch! Basically Unity's UI system marks an object to be rebuilt when something has changed, and then it rebuilds it. If something happens while it is rebuilding that marks it for another rebuild, you'll see this message. In general, the worst thing that you can expect is that the UI will be rendering out of sync with what you expect.
Is PaneText a subclass of HyperText, or something that triggers an update for HyperText? If you're having difficulty narrowing it down, you can email a small project or package to
bu...@candlelightinteractive.com and I'll see if I can help figure it out.