I just updated from 14.04 to 14.10 yesterday. Today I stumbled on a bug in Image Viewer. Tried to report as per https://help.ubuntu.com/stable/ubuntu-help/report-ubuntu-bug.html but after "Collecting problem information", it just leads to "The problem cannot be reported. The report belongs to a package which is not installed." So here I am at askubuntu. This was my first time using 'ubuntu-bug', and I was unclear on the correct syntax for the program name, like, case sensitive? space between words, or no space? Either way, I figure I did it right given that "Collecting problem information" launched.
Bug: In Image Viewer, with an image displayed in "fit to screen" size, I left-clicked turning the mouse pointer into a closed-hand 'grabber', and tried to drag the image a bit. The image doesn't move of course, as the whole thing is already displayed. But then releasing the mouse button, the pointer remained like a little thumbnail of the image, but only the lower half. The upper half was 2 pointer arrows, side by side. I could not undo this and get a normal pointer again, until after reboot. Before that, I tried closing Image Viewer, then closing all other programs, then looking at Settings>Mouse... nothing would recover my pointer back to normal, until reboot. I've reproduced this problem 4 times now, needing 4 reboots.
Notably, when viewing an image in full-size where it exceeds the screen res, the grab & drag function works properly- pointer returns to normal after releasing mouse button.
As an unannounced 2-fer here, I'll also note that "Cheese Webcam Booth" would not open at all, resulting in an error message. Trying the same 'ubuntu-bug' report process above resulted in the same "The problem cannot be reported. The report belongs to a package which is not installed" message. But just now I tried launching CWB again, first time since most recent reboot, and it appeared to launch normally.