Overlay doesn't get appropriate margin-top and Shortcuts panel overlaps its top. For admin pages & Seven theme this makes local task's tabs not accessible (see the screenshots 1 & 2)
Drupal 7.19 + jQuery Update with JQuery 1.8.
Tracing JS revealed that error occurs in 873rd line of the
displacement = lastDisplaced.offset().top + lastDisplaced.outerHeight();
where calling jQuery function
lastDisplaced.outerHeight() instead of a expected number returns HTML (see the 3rd screenshot).