mod_rewrite works but is causing error log spam

[EA Durbin]

I have enabled mod_rewrite on my server and it successfully rewrites URL's and works nicely, but then it logs the URL to be rewritten as "File does not exist" .... in the error log

My http.conf section

<VirtualHost *:80>
    ServerName customers.foo.com
    ServerAdmin [e-mail]
    DocumentRoot /var/www/portal
    RewriteEngine On
    RewriteCond %{SERVER_PORT} ^80$
    RewriteRule ^/logout$ /portal.php?iLogout=1 [NS,L]
    RewriteRule ^/register/submit$ /register.php?sAction=register [NS,L]
    RewriteRule ^/register$ /register.php [NS,L]
    RewriteRule ^/password/submit$ /reset.php?sAction=reset [NS,L]
    RewriteRule ^/password$ /reset.php [NS,L]
    RewriteRule ^/login$ /index.php [NS,L]
    ErrorLog logs/cust_error_log
    CustomLog logs/cust_access common
</VirtualHost>

Rewrite Log lines

192.168.0.209 - - [01/Feb/2008:12:48:54 --0600] [customers.foo.com/sid#80519538][rid#80744800/initial] (3) applying pattern '^/password/submit$' to uri '/password/submit'
192.168.0.209 - - [01/Feb/2008:12:48:54 --0600] [customers.foo.com/sid#80519538][rid#80744800/initial] (2) rewrite '/password/submit' -> '/reset.php?sAction=reset'
>

and resulting error log line

[Fri Feb 01 12:48:54 2008] [error] [client 192.168.0.209] File does not exist: /var/www/portal/password, referer: http://customers.foo.com/password/submit
>

Any suggestions?