r - Rで時間のフォーマットが失敗するのはなぜですか

Question

strptime('16/Oct/2005:07:51:00',format='%d/%b/%Y:%H:%M:%S')
#[1] NA

私のRバージョンは3.0.2 (2013-09-25) で、次のとおりです。

strptime('16/2005:07:51:00',format='%d/%Y:%H:%M:%S')
#[1] "2005-11-16 07:51:00"

"Oct"失敗し%b、以下も失敗します。

strptime("Mon Oct 28 00:19:35 +0800 2013", format="%a %b %d %H:%M:%S %z %Y")
#[1] NA

sessionInfo()
#R version 3.0.2 (2013-09-25)
#Platform: x86_64-pc-linux-gnu (64-bit)
#locale: 
#[1] LC_CTYPE=zh_CN.UTF-8       LC_NUMERIC=C               LC_TIME=zh_TW.UTF-8       
#[4] LC_COLLATE=zh_CN.UTF-8     LC_MONETARY=zh_TW.UTF-8    LC_MESSAGES=zh_CN.UTF-8   
#[7] LC_PAPER=zh_TW.UTF-8       LC_NAME=C                  LC_ADDRESS=C              
#[10] LC_TELEPHONE=C            LC_MEASUREMENT=zh_TW.UTF-8 LC_IDENTIFICATION=C       

#attached base packages:
#[1] stats     graphics  grDevices utils     datasets  methods   base     

#loaded via a namespace (and not attached):
#[1] tools_3.0.2