Let me first say that two communications with Photo Bucket support have brought caring help and concerned tones about what they could do to fix current problems. One-to-one human help. However, a year later I find myself getting het up on further issues.
It's that box on the right that was giving me the problems. It should, at a pick, show an ethereal 'Copied'. Mine would not until I clicked on the photo left/right arrow and got the next picture on the screen. I would then go back to my original picture and it would copy. The other night it wouldn't copy whatever I did. Couldn't even 'block'/select the address to copy it the hard way. When I later tried it with a folder with only one photo in it, it worked.
The other issue:
I always used to select the bottom option and put Paste in the PPRuNe screen. Simple, though an oversize would be tedious and bring the wrath of the mods. When I joined the Seiko watch restoration forum they have masses of fantastic photos of the works and to post on their (unknown) site software, one had to do what was suggested above. Different, but it worked well.
Because PB has been so caring in the past, I feel inclined to work with them a bit longer. The library is not bad but I do feel there may be an issue with the number of photos in any given folder.