If I accidentally click on an alias to a disk image that isn't mounted, the Finder pops up the password prompt with Cancel and OK buttons. But every time I click Cancel, it pops up again. It will not give up. My only option is to mount the disk image or Relaunch the Finder.

I know it's been years since Apple fired their entire verification staff, but they really need to rebuild it with people who have the authority to enforce bug fixes and who actually like Macs.