I have the same problem..
Have you figured it out yet?
I've searched for the Contribution editor or spreadsheet and all I could find was the attribute spread sheet. But I don't know what i'm supposed to do in this editor.
When I select the crazy vertex, and pressing 'all' in the editor i'm getting this:
Caching Node State Envelope Relative Tweak
tweak6 | off | normal | 1 | on |