If you use cmd-up in a text field in Safari, you are moved to the first line, but it is not spoken. Pressing up arrow will not speak the line either; you must down arrow, then up arrow, to hear the first line.
Bug First Encountered
How often the bug occurs
Press down arrow, then up arrow, and things will work as expected. It's only the first time you jump to the top that there seems to be a problem.