I am currently using Ubuntu 10.10 and now have an issue with my audio system

I am currently running Ubuntu 10.10 and have just now developed a problem with my audio system. The system does still have sound, but I can no longer change the volume, or select what sound scheme to use, or have any control what so ever over the audio system. I tried booting up into restore mode, but that did not help anything. If I select sound from system>preferences> sound, a little window comes up in the center of my screen that says Waiting for sound system to respond, but it never does. Also, the overall performance of my machine has also seemed to have slow down somewhat, responding to commands slowly, especially when I hover the mouse over items in the menu, it takes a while for it to highlight, and then display the other list of choices from that. How can I correct this problem? I have rebooted my computer several times, but nothing seems to help.