Comment 46 for bug 569680

I just got another error with the stock kernel sources. It isn't something introduced by an Ubuntu patch.

I did some more google searching, and came across this:
http://www.google.com/search?q=site:kerneltrap.org+%22failed+command%3A+READ+DMA%22

It looks like similar problems have been cropping up for various people over several different kernel versions. I don't really know what to do next.