On TB9.129, Mac OSX Sierra...
1. Create a thought and attach a URL to it.
2. Make that thought a pin
3. If you click on the icon for that pin, the URL will only open in the external browser if the pinned thought is the currently active thought. When you change the plex to another active thought, clicking on the pinned thought's icon does not open the browser.
Here is what is produced in the output.log file when I try to open a pinned URL when its thought is NOT active:
2016-10-31 03:38:25.6248 | INFO | TheBrain.Graphics.Imaging.ImageManager |  Loading image /Users/rlopez/Documents/Brains/U01/B02/6ce0fcd9-995e-55ab-9d3b-be2043b08d02/.data/Icon.png
2016-10-31 03:38:25.6253 | INFO | TheBrain.Graphics.Imaging.ImageManagerDataStore |  Image cache is now approximately 21.3 MB
2016-10-31 03:38:32.4425 | DEBUG | TheBrain.Client.NotesContentController |  AttachmentSource will be set to Zimbra Web Client Sign In
2016-10-31 03:38:32.4483 | DEBUG | TheBrain.Client.NotesContentController |  Loading notes for Zimbra Web Client Sign In - True True True
2016-10-31 03:38:32.4588 | DEBUG | TheBrain.Client.NotesContentController |  AttachmentSource set to Zimbra Web Client Sign In notesEditorWebView.IsEditorReady True
Interestingly, NOTHING appears in the output.log file when I open a pinned URL when its thought is active.