wp duplicating blog page all over my site

Thinking about this some more, it must be related to my .htaccess file I think. I did amend it a couple of weeks ago when I was trying to install and set up the wp feedburner plug in. Anyway, this is what my .htaccess file looks like:-

RemoveHandler .html .htm
AddType application/x-httpd-php .php .htm .html .phtml

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

Does this look ok? Could the mod_rewrite rule be causing this do you think?

Thanks for any help