I've done quite a few building outlines tonight utilising Bing imagery in P2.
However on more than one occasion, saves were not happening (according to the dialogue box), so I cancelled after a few minutes of waiting. At one point I cancelled twice before eventually getting a save completed indication after a third attempt. Going back to tag the building later in P1, I got flashing red nodes indicating dupe nodes. I found that building outlines had in fact been drawn 3 times over the top of each other. So the database was getting the info on each save but the P2 editor at my end was not getting confirmation that the data was being saved. My experience of P2 to date is that I get hit with random bugs with no pattern to them, which to me seems to be some sort of connectivity problem between the editor in the web browser and the server that stores the data