WordPress 2.9.2 htaccess curruption issue strikes again (in Patched site)

The htaccess file below crashed the site with an internal server error (500). This site has the misc.php patch that’s discussed here:

WordPress Bug #11903

Apparently something else is at play here or the patch is not fully addressing the issue. 3 sites went down yesterday. 2 today (so far). All sites have the patch file that’s referenced in the bug track link above.

The issue appears to be a currupt htaccess write operation which results in a malformed htaccess file (see code in red below).

 AuthName mysite.net
 AuthUserFile /home/mysite/public_html/_vti_pvt/service.pwd
 AuthGroupFile /home/mysite/public_html/_vti_pvt/service.grp
 Options All -Indexes

 # BEGIN WordPress

 # BEGIN WordPress root
 <IfModule mod_rewrite.c>
 RewriteEngine On
 RewriteBase /
 RewriteCond %{REQUEST_FILENAME} !-f
 RewriteCond %{REQUEST_FILENAME} !-d
 RewriteRule . /index.php [L]
 </IfModule>

 # END WordPress root
 dule mod_rewrite.c>
 RewriteEngine On
 RewriteBase /
 RewriteCond %{REQUEST_FILENAME} !-f
 RewriteCond %{REQUEST_FILENAME} !-d
 RewriteRule . /index.php [L]
 </IfModule>

 # END WordPress root