The new default mode got some performance and usability issue.
http://www.pcmag.com/article2/0,2817,2372489,00.asp
http://www.google.com/support/forum/p/Web+Search/thread?tid=0ef4a1565674f2b1&hl=en
Scroll to bottom of page in result, choose "switch to basic version" to go back to the old version.
Scroll to bottom again to switch back to standard version
