Did you use the debug tool recently? There is an event there to toggle on/off the personal info page. If not, it's possible there is a bug somewhere. Do you remember what were you doing before the page stopped working?
I did use it once to just get a little feel so I think that is the reason, so I will check
For now, I'll treat it as a mistake, but I'll keep an eye out for this in the future, just in case.
