Logged into web administrator http://PlutoMachineName
Followed the wizard items on the left-hand side of the page starting at the top. Answered the questions in the first section apparently incompletely (optional name/address/timezone/etc.)
Went through each section item by item and eventually got to the interfaces page. Upon opening, nothing appeared in the right-hand box. Selecting any manufacturer (ok...I didn't check *all* the manufacturers) and item still nothing appeared. After repeated attempts to make something appear I assumed I'd screwed something up earlier in the process.
W/ the Interfaces window still open I went back and started redoing all the settings from the beginning and being careful. Quickly noticed an item not filled out on the first section (timezone/default language). Filled that section out again. Went back to the Interfaces window and noticed that it was now populated on the right-hand side.
I'd guess it was default language.