constantly resetting permalinks and getting 404s on blog posts

Hi there! Hoping someone may have run into this before?
Every time my editor creates a blog post on our main site in a multisite installation she gets a 404 on the blog post itself. I go in to permalinks and resave the structure and then it works. But I need a permanent fix. I have checked the .htaccess file and it shows this at the bottom:
# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
# add a trailing slash to /wp-admin
RewriteRule ^wp-admin$ wp-admin/ [R=301,L]
RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule ^(wp-(content|admin|includes).*) $1 [L]
RewriteRule ^(.*\.php)$ $1 [L]
RewriteRule . index.php [L]
</IfModule>
# END WordPress

Which seems correct? Any advice appreciated!
Andrea