I am trying to save the edit of a EditorGridPanel with a JsonStore. Changes automatically mark rows as dirty, so they are sent with the save fine. My store has pruneModifiedRecords set to true. Still, removed records are not handled UNLESS I edit one of the fields as well. What am I missing here?

    var GlossaryStore = new Ext.data.JsonStore({
        // destroy the store if the grid is destroyed
        autoDestroy: true,
        autoSave: false,
        // load remote data using HTTP
        url: 'GlossaryStore.php',
        pruneModifiedRecords: true,
        root: 'Terms',
        writer: writer,
        fields: ['Delete', 'ID', 'flgDelete', 'Term', 'Definition', 'Created', 'Edited', 'Delete'],
        sortInfo: {field:'Term', direction:'ASC'}
    }); // end var GlossaryStore = new Ext.data.JsonStore({
the save button just triggers this javascript function:
function SaveChanges(GlossaryStore)
    // trigger the save to the db
    // if the save was successful, then commit the changes to the grid.
} // function SaveChanges()
without including a ton of extra code, here is the panel the store is in:
    var grid = new Ext.grid.EditorGridPanel({
        id: 'GlossaryGrid',
        store: GlossaryStore,
        cm: cm, /* column model */
        sm: extCheckBox, /* checkbox selection model */
        renderTo: 'editor-grid',
        width: 780,
        height: 400,
        autoExpandColumn: 'term', // column with this id will be expanded
        title: 'Glossary Terms',
        frame: true,
        clicksToEdit: 1,
        tbar:[{ /* removed for brevity */}]