Memstick Images not working (mountroot prompt)

Hello,

I need to Install FreeBSD 10 on my laptop to have Wireless support for
my card (ath) however I tried all of the available memstick images at:
ftp://ftp.uk.freebsd.org/pub/FreeBSD/snapshots/amd64/amd64/ISO-IMAGES/10.0/

And none of them works... I've tried 2 different pen drivers, one of
those is a generic cheap one, and another is a "DKingston DT 100 G2"

When typing "?" in the mount root prompt I see my ssd and hdd are
listed, but not the memstick (which I assume it should be da0).

I had no problems with the 9.1 stable image using the same memstick!

Thanks