Interesting you have had the same problem with the picture button that I have had. Cache/history emptying etc didn't work for me and I will now enter a support request - if Rick's advice doesn't work for you, suggest you do the same. you .
Meanwhile, best short term solution I found was to hit the enter picture button for image 2, and if that doesnt work, picture 3 and so on. When the picture loads, it seems to automatically go in to space 1 and therefore be OK for the gallery anyway.
Alternatively, save the item without a picture (and if you are listing a lot of things at the same time a reminder to yourself in the title that there was no picture - an asterisk or question mark for example), then go back into it in a few minutes and try again.
Good luck!