As I already informed in issue JRA-6196, there's an error in the Filter Statistic portlet, and it is not fixed in 3.1.1 (despite this is what supposed to do, as you said in JRA-6196).

The description of the problem is the following:

If you create a filter using an specific field (status, for example), and then use the portlets Statistics or TwoDimensionalStatistic to show this filter using the same field you chose to create filter, the information the portlet shows is right, but when you click in one of the links (anyone of the statuses, in the example), it will show you not only that status, but ALL of them.

This is an example of the URI that fails:

/jira/secure/IssueNavigator.jspa?reset=true&statusIds=1&statusIds=3&statusIds=10000&statusIds=10003&statusIds=10004&statusIds=10005&assigneeSelect=issue_current_user&statusIds=10005

As you can see, an "&statusIds=10005" is added at the end of the URL because of the status you clicked in, but it has no effect due to the other "statusIds" at the beggining of the URI (the ones which belongs to the filter itself, that in this case should be removed).

I hope to explain myself good enough, english is not my first tongue and is difficult to me to express things exactly.

Regards,

Andrés.