How to use div -ids in url to jump to specific post…Is trailing slash the culprit?

First, I’d recommend using “pretty permalinks” over the default query-string structure. This will eliminate most of your problems from the getgo. It will turn your http://www.example.com/?cat=15#post-170 urls into http://www.example.com/category/category-slug/#post-170 and the browser will move correctly to the post’s position in the page.

That said … Yes, you can remove the trailing slash. The trick is to add a rule to your .htaccess file:

#remove trailing slashes
RewriteCond %{HTTP_HOST} ^(www.)?yourdomain\.com$ [NC]
RewriteRule ^(.+)/$ http://%{HTTP_HOST}/$1 [R=301,L]

(This is taken from a Drupal tutorial that does the same thing …)