disabling the css properties overflow:hidden and position:relative of all parent html elements sort of fixes this issue, but destroys layout -> not a real fix.

ACTUAL FIX: (theme/canvas/style/pagelayout.css)

- #page-content #region-main-box .region-content {

    padding: 0;

}

+ #page-content #region-main-box .region-content {

    padding: 10px 0 0;

}

Since this problem only relates to certain CORE themes which use CANVAS as a parent theme, you only need to check the following themes: Boxxie, FormFactor, Leatherbound, Serenity & Splash. All other themes EXCLUDE pagelayout from CANVAS theme.
INSTRUCTIONS FOR TESTING:
1. FIRST with editing ON create an anchor (bookmark) using the HTML part of the text editor at about Section 5 of a course page (i.e) <a name="test"></a> SAVE
2. In Section 0 (zero) of the same course page create a link back to the anchor (i.e) <a href="#test">anchorlink</a>
3. Turn Editing OFF
4. CLICK on the link: the page will then scroll down to the section which was bookmarked.
5. SCROLL back up to the top of the page -> check to see headline h2.headingblock is fully visible