Comment 6 for bug 595908

Edit to my last comment (and removing myself from the bug report). It looks like the cause of the error in my case was that I had installed the i386 version of 12.04, not the amd64 version. I created a new amd64 image of 12.04, and all flavors of pbuilder create now work.

(Note to those who come across this error while running 12.04 in a VMWare image from OS X -- check http://support.apple.com/kb/HT3696 to see if your computer can support a 64-bit OS. If it can, install the amd64 version instead of the i386 version. You can verify which version is installed by typing: "file /bin/ls" at the ubuntu terminal prompt.)