This does not happen every time, and I have not figured out when/why it occurs. It occurs maybe 10-15% of the time randomly. If I create a post, edit one, or create a conversation, sometimes the progress bar will just keep loading forever and the page won't refresh. If you do reload or go to another page, the post is saved. I had several users report this after I upgraded to XF 1.5. I also recently upgraded to Flat Awesome for 1.5.0 and the only other thing I added was "Stay logged in checked by default."