I was switching back and forth between the nv and nvidia driver... I could have sworn I changed it back before copying it to the web server (updated it since your post). I had the Load "glx" line in before, and I also tried commenting out the Load "dri" line (I think the log is actually from when dri was commented out). Neither seemed to help, or have any discernable effect other than changing the messages in the log, though.
Thank you for taking a look.