rocknbil - 6:47 pm on Jun 26, 2010 (gmt 0)
Ignore it no, someone comes to your site and gets a 404, **poof** goes one more opportunity.
RewriteRule ^(.+)\.htm$ /$1.html [R=301,L]
Should rewrite any request for .htm to .html, if it doesn't exist, let your 404 display. Windows servers will have an equivalent.