1TB drive of quality open content on XO/XS--won't boot

[Holt]

Is there a way to boot a large USB hard drive attached to an XO?
At our XS Community Sprint this week outside Toronto, we've been unable 
to boot XOs with the 700+ GB drive(s) containing very polished open 
content provided by http://internet-in-a-box.org
The XOs (eg. XO-4 etc) refuse to auto-boot, leaving the screen at the OK 
prompt.

FYI our 1TB disk is a nearly complete snapshot of:
* Wikipedia-in-41-languages, thumbnails for most all images
* OpenStreetMap for the whole world cached at all zoom levels for fast 
display
* Gutenberg Prjct's full collection of 40,000+ books, images
* Khan Academy's ~4000 video classes, etc

Does firmware currently block the mounting of all large USB drives -- 
NTFS in this case if not other filesystems?
Might there be a workaround so isolated XO servers in Haiti (etc!) can 
hopefully auto-boot with this quality free content?
Cheers!

--
Help kids everywhere map their world, at http://olpcMAP.net !