There is definitely a problem, but I have found a temporary work-around.
First of all, the cache feature DOES seem to be working okay. I needed to refresh my ftp client to get the cache to show as purged or to see new thumbnails in it.
HOWEVER, there is still a problem with the image size feature. I don't know how long the problem has existed, or if it's new in version 1.1.5, but image file sizes aren't calculated and FF sits in an endless state of trying to calculate.
ALSO (nickvergessen, this is a clue
), I discovered, after disabling the image size on thumbnail feature that there was still ONE image (image X) that FF always seemed to want to calculate the size of. Very strange. The image is not special, it's not resized because it's fairly small, and it's one of our recent images (uploaded during version 1.1.4 implementation). However, I did find one image in my uploads directory that was uploaded after that by another user (during 1.1.5), that had no database entry. It was a large file, and a smaller copy of it (image Y) was uploaded immediately afterward by the user. So I suspect the user received an error during the upload, and then resized his image to try again - and was successful. But still this file was sitting there, without a db entry. I used the tool in the cleanup gallery ACP section, and discovered that was the only file that needed removal (I do this occasionally). Once that file was removed, the OTHER image (image X) became correctly handled by FF and by the gallery. FF no longer tries to calculate its size and no longer sits in a waiting state.
Later today or tomorrow, I will try to duplicate the problem and see if it returns by forcing an error and uploading a large file, then a smaller copy.