I'm installing Arch on a SD card for my Beaglebone Black using the "try it before you install it" Ubuntu 13.04 image. I got these errors...
$this->bbcode_second_pass_code('', '
root@ubuntu:/home/ubuntu# tar -xvf BeagleBone-bootloader.tar.gz -C boot
./MLO
tar: ./MLO: Cannot change ownership to uid 1001, gid 1001: Operation not permitted
./u-boot.img
tar: ./u-boot.img: Cannot change ownership to uid 1001, gid 1001: Operation not permitted
./uEnv.txt
tar: ./uEnv.txt: Cannot change ownership to uid 1001, gid 1001: Operation not permitted
tar: Exiting with failure status due to previous errors
')
Even with these errors, the board booted up normally. I hope it's safe to ignore them.