For example forums and such...but more importantly members areas on sites with logins.

You just don't have natural keywords there, so the ads are crap like UML tools, CGI email forms, SQL made easy....because adsense takes keywords from nav menu that has words like "inbox" and "email" in it.

You just get a ton of technical web related stuff that has nothing to do with the website in question.

Tips?

Section targeting is the first thing that comes to my mind.
http://www.google.com/adsense/suppor...y?answer=23168

Make sure your forum threads have content.

Adsense is built to be on pages that contain content. Add content and your adsense ads will follow along.

Forums were just an example, this is more about members pages on sites with members areas

Understood but my point is simple. Adsense was created to be on content pages. If you have them on non-content pages, read the adsense quality guidelines and make adjustments. I believe you will see a change in your own revenue as you make sure adsense appears only on pages with content.