Here is what I tried. When having same problem.
I clicked preview 1st, left that page open.
Then clicked on save listing (not ready to post) & it worked a few times. Even though I don't know it worked until I go back in to look at saved listings.
I used 64 bit version of IE 9 for everything but image upload.
I seem to be "special" getting a problem all my own with constant pop-ups in my 32 bit version of IE 9. (Yes you can have 2 separate versions & the 32 bit is less secure.) Anyway, when I thought I lost my work in 64 bit, I found it was saved in 32 bit. Of course I can hardly function with the constant pop-ups.
This started happening many days ago. 1st it was a fake survey that had Auctiva logo, with chance to win $50. Which wouldn't go away. Then I got a car insurance pop up in new web broswer. Blocking url as unsafe site didn't work. Just rambling now. Hope 1st part of my msg helps for some.