Installer tries to be smarter than the user

The Live CD, while either booting into a live system, or doing a Trisquel install, refuses to boot if the CPU does not report PAE as one of it's features. Some CPUs, like the Pentium M, do not report that they have PAE, when in fact they do,and the installer refuses to start.

Read this thread for more information.
http://trisquel.info/en/forum/boot-trisquel-computers-without-pae