Clicking a link to content in a tab does not open the tab and display the linked content. It doesn't matter if you are linking to an anchor or a heading.
Example:
1) go to this page:
http://wikis.sun.com/display/SRS/SwapDrop+Language#tab:Data-Types
2) Click on String Operators tab.
3) Click on the boolean link in Output Parameters section.
4) I was hoping this would open the Data Types tab and
go to the anchor referenced.
From Igor:
That's because Confluence renders URI hashes (anchors) prefixed with page name.