The "mapped style" link next to an attribute doesn't do anything when you click it. It's supposed to switch to the style pane and focus the mapped style declaration. This is an inspector regression.
Console messages: 2007-04-24 01:32:33.858 Safari[1958] JS exception: Undefined value on file:///WebKit/WebKitBuild/Debug/WebKit.framework/Resources/webInspector/inspector.js line 1116 2007-04-24 01:32:33.859 Safari[1958] Stack trace: selectMappedStyleRule (anonymous function) Forgot to mention how to reproduce: open the URL, open the inspector, navigate to the body element, there you should see a "mapped style" link for the bgcolor attribute. Click it.
Created attachment 14150 [details] Patch
Landed in r21067.