Permalinks and .htacess problem

I trying to set the permalinks to this custom structure: /%postname%/

but keep getting a error message to update the .htaccess file and to include:

‘<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ – [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>’

I edited .htaccess but still get the error (and I’m a bit stupid with .htaccess).

When that did not work I also renamed the old .htaccess file and created a new one with only the above mod_rewrite rules in.

I also changed the permissions eventually to 777 but keeps getting the same error to update the .htaccess file

When I save a new page or post it seems that permalinks are working ok.

But when a visitor is redirected from AWeber signup form to a specific wordpress page it seems that the url is rewritten (by wordpress) and the visitor is sent to the rewritten url (with nothing on) instead of to the specified landing page. I’m not sure if my assumption is correct and if this problem is related to the .htaccess error, but if I can get the .htaccess error fixed I will quickly see if my other problem is sorted out.