There may be other unforeseen breakage primarily in the handbook portion of the wiki.
The Table Of Contents section of each "PC-BSD® Users Handbook" page may be the best workaround.
Using Brasero in GNOME
Brasero is an easy to use CD-ROM/DVD burner included with the GNOME desktop. To launch Brasero... and click ...", as seen in Figure X-XX:
A dialog window will be displayed and you will be able to select your .iso file. Select it and click "OK". The next window, seen in Figure X-XX, allows you to select your CD-ROM drive, as well as a few other options. Leave these options as default. Click "Start" and Brasero will begin to burn your DVD: