My website contains .htm and .php pages!

[GovindIRC]

This post is deleted!

[donford]

It should have no effect on SEO. If you're really concerned about the difference you can take the SEOMoz approach and drop all file extensions with .htaccess. For the record our corporate site uses both .html and .php extensions and I have noticed no difference in SEO rankings.

RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}.html -f
RewriteRule ^(.*)$ $1.html

Replace html with your file extension, eg: php, htm, asp

[Bromtec]

You can always change your .htm pages to .php so everything is consistent.  Changing .htm to .php won't cause any problems.

Please note that changing php to htm on the other hand will break the php code (unless you remove the php with a rewrite as donford mentioned.)