I've got default report date to load set to "today". When I click on the Dashboard link in the TopMenu it statically links back to date=yesterday totally ignoring this setting (and even reverting the date I chose before switching to the settings).
Ok - to reproduce: Install fresh Piwik 1.2, then check for this bug. If you go to settings after installation default report date will be set to today in UI, once you save this setting again the bug disappears and the link correctly goes to "date=today".
(In ) fixes #2138