FormPanel is not displaying fieldset and fields

[KallDrexx]

I'm confused on why my formPanel won't render the fieldset or the fields. When I add this to my TabPanel, I am correctly seeing the tab with the title set, toolbar rendered correctly, but nothing else. Through Chrome's debugger I have verified that buildDetailItemArray() is being called, so I am confused as to what I am doing wrong.

MyApp.panels.RelationshipDetails = Ext.extend(Ext.FormPanel, {
    closable: true,
    relationshipId: null,
    documentId: null,
    title: 'Relationship',
    initComponent: function () {
        if (!this.verifyRequiredData()) {
            MyApp.panels.RelationshipDetails.superclass.initComponent.call(this);
            return;
        }

        // Build components
        this.tbar = this.buildToolbar();
        this.items = this.buildDetailItemArray();

        MyApp.panels.RelationshipDetails.superclass.initComponent.call(this);
    },

    verifyRequiredData: function () {
        // Verification code here
    },

    buildDetailItemArray: function () {
        return [{
            xtype: 'fieldset',
            title: 'Details',
            collapsible: true,
            autoHeight: true,
            items: [{
                xtype: 'hidden',
                name: 'Id'
            }, {
                xtype: 'textfield',
                fieldLabel: 'Name',
                name: 'Name'
            }, {
                xtype: 'textfield',
                fieldLabel: 'Description',
                name: 'Description'
            }, {
                xtype: 'button',
                text: 'Save',
                name: 'saveButton'
            }]
        }];
    },

    buildToolbar: function () {
        return new Ext.Toolbar({
            // Toolbar Config
        });
    }
});

[KallDrexx]

After doing more debugging I am even more confused.

If I comment out the this.tbar line, the items show correctly. As long as this.tbar is being set though, the form does not show. Anyone have any insight into why?

[KallDrexx]

If anyone is interested, this issue was caused because my Panel had no height specified. By adding autoHeight: true into the config, everything works correctly!