Joomla administrator login give 404 error - Joomla! Forum - community, help and support

after enabling user friendly url , rewrite mod , editing .htaccess website working great can't access administrator section (got 404 - component not found)
the .htaccess follows:

directoryindex index.html index.shtml index.xhtml index.wml index.perl index.pl index.plx index.ppl index.cgi index.jsp index.js index.jp index.php4 index.php3 index.php index.phtml index.htm home.htm default.htm index.fcgi default.html

indexignore .htaccess */.??* *~ *# */header* */readme* */_vti*
rewriteengine on
# security reasons, option followsymlinks cannot overridden.
options +followsymlinks
options +symlinksifownermatch
rewritecond %{script_filename} !-f
rewritecond %{script_filename} !-d
rewritecond %{request_filename} !-l
rewriterule ^(.*)$ index.php/$1

<limit post>
order deny,allow
deny all
allow all
</limit>
<limit put delete>
order deny,allow
deny all
</limit>

please ..
note:

i'm using password protect directory on /administrator there's .htaccess inside /administrator follows:

authtype basic
authname "security"
require valid-user
authuserfile "/home/account/.htpasswds/public_html/administrator/passwd"