Use case:

1. Go to "Visitor Browser" widget on dashboard. (Rows 1-5 of 14 displayed)
2. Click on graph display type
3. Pick up some additional metrics ("Visitors")
4. Switch back to table view. (Rows 1-5 of 5) !!!!

That happens because jqplot.js adds extra "disable_generic_filters=0" to request.

dataTable.param.disable_generic_filters = '0';

And on ResponseBuilder this variable causes immediate DataTableGenericFilter processing. (as DataTableGenericFilter called on getResponse() it is triggered twice)

if(0 == Piwik_Common::getRequestVar('disable_generic_filters', '0', 'string', $this->request))
               {
                       $genericFilter = new Piwik_API_DataTableGenericFilter($this->request);
                       $genericFilter->filter($datatable);
               }

Removing that lines from ResponseBuilder.php and(or) jqplot.js fixes bug.
However I'm not sure about side effects of this.