Speech No Longer Working

[audiodan]

For a while, after I upgraded to Leopard, text to speech worked. It announced the time, helped me read things and more. I am just noticing now, that it stopped working. I can't change, or hear the voices in system preferences, and I can set key commands to hear highlighted text, but it doesn't work! When I press it in safari, the Edit menu flashes for a second, but that's it.