i cannot untar the file::

home/user/MyDocs # tar -xzvf wl1251-maemo-0.2-power49\+pre50.tar.gz
wl1251-maemo/
wl1251-maemo/cfg80211.ko
tar: wl1251-maemo/cfg80211.ko: Cannot change ownership to uid 1000, gid 1000: Operation not permitted
wl1251-maemo/wl1251_spi.ko
tar: wl1251-maemo/wl1251_spi.ko: Cannot change ownership to uid 1000, gid 1000: Operation not permitted
wl1251-maemo/wl1251.ko
tar: wl1251-maemo/wl1251.ko: Cannot change ownership to uid 1000, gid 1000: Operation not permitted
wl1251-maemo/rfkill_backport.ko
tar: wl1251-maemo/rfkill_backport.ko: Cannot change ownership to uid 1000, gid 1000: Operation not permitted
wl1251-maemo/mac80211.ko
tar: wl1251-maemo/mac80211.ko: Cannot change ownership to uid 1000, gid 1000: Operation not permitted
wl1251-maemo/compat.ko
tar: wl1251-maemo/compat.ko: Cannot change ownership to uid 1000, gid 1000: Operation not permitted
tar: wl1251-maemo: Cannot change ownership to uid 1000, gid 1000: Operation not permitted
tar: Exiting with failure status due to previous errors
/home/user/MyDocs #