The error message by some components i.e. Datebox is not shown in Firefox version 10.0.12 ESR. It works fine with the actual Firefox (version 40.0.3).
See http://zkfiddle.org/sample/21efjle/3-ValidationMessageNotShown

Expected result:

The datebox should have red border, and an errorbox appears with the "error message" message.

Actual result:

The datebox has red border, but an errorbox does not appear. It appears on top of the window, when the user scrolls the mouse down or up.