Imgur albums disable all keyboard shortcuts in Safari

Looking at an album that uses keyboard shortcuts for selecting between multiple images will completely disable default Safari shortcuts. For example, Cmd+W doesn't close the window, Cmd+Q doesn't quit, and backspace doesn't go back to the previous page. The mouse is required to do anything, which is extremely annoying.
This is using Safari version 5.0.3 (5533.19.4) on Mac OS X 10.5.8.