Hi, I've opened a bug in Jira (https://issues.apache.org/jira/browse/WICKET-2550) regarding the DatePicker behavior (in Wicket 1.4.1 and above). The issue includes a QuickStart in order to reproduce the bug. It seems that the DatePicker introduces a bug when it's included in a WebPage that can change its state by using an AJAX component.
For example, in the QuickStart the home page contains a LoadableDetachableModel that returns a list of strings. The page contains a boolean field (of course persisted) that determines whether the list has elements or not. When the user clicks an AJAXButton, that boolean value is modified so that the page displays not an empty list. When the user clicks another non-AJAX button he is redirected to another page. Once in this page, if the user clicks the browser back button it's expected that Wicket loads the previous page from the PageStore (the one that has the not empty list!). However Wicket apparently loads the first one (the one with an empty list of strings). If we remove the DatePicker behavior from the TextField component everything works well. Thank you in advance, MartÃn.