Hi, Maybe this will help
after upgrading udev / kernel sources i've found in dmesg that my camera (olympus) which uses mass storage protocol was found as a /dev/uba1 so maybe your USB stick will also be as such device.
if not paste your dmesg messages what it says while plugging into USB stick. Or maybe you don't have usb-utils package which helped me to run my camera properly.
Greets Pawel -- gentoo-user@gentoo.org mailing list