What does Debug [0/0]: mean?

What does it mean when Debug [0/0]: appears at the top of the admin panel. It only appears on the product update page, and [0/0] would tend to suggest that nothing is wrong, but how do I turn it off or make it go away?

Prior to this there must have been an error (I was changing product features) and there was a lot more Debug information at the top, but after I tried to put things back how they were, it changed to Debug [0/0]:

It seems like that error has turned on some kind of debugging that now won't go away.

Any suggestions?

The problem seems to have worked itself out - I left it overnight and now it no longer appears.