It happens that when you insert a pendrive (I think >=8GB), the kernel reports it's size to be 15 EiB, as a result fdisk, parted and dd fail. There has emerged a patch -- http://permalink.gmane.org/gmane.linux.usb.general/65976 Reproducible: Always
This is is linux patch 3.4.5 which is available in both vanilla and gentoo-sources flavors. http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=6a0bdffa0073857870a4ed1b4489762146359eb4