ExtJS - Hiding ComboBox based on other Combo value

I'm having a weird issue where I'm defining a combo has hidden:true, which works fine, but when I show the combobox and select a value from it, it hides. Here's some example code:

(I'm using some custom extended ComboBox's, but that's not the issue)

First ComboBox:

var bulkImportType = {
    xtype: 'ibwComboLocal',
    fields: ['id', 'name'],
    data: [[1, '3rd Party Tag'], [2, 'Image'], [3, 'Template']],
    fieldLabel: 'Type',
    listeners: {
        'select': function(combo, record, index) {
            if (record.get('name') == 'Template') {
                this.bulkImportTemplateCombo.show();
            } else {
                this.bulkImportTemplateCombo.hide();
            }
        }, scope: this
    }
};

Second ComboBox (shown only when the first Combo == Template)

var bulkImportTemplate = {
    xtype: 'ibwComboJson',
    hidden: 'true',
    url: 'http://itads-dl06.tweb.aol.com:3080/IBW/templates?returnJson=1',
    ref: '../bulkImportTemplateCombo',
    root: 'templateList',
    fieldLabel: 'Template'         
};

The hiding/showing works fine, but it seems that when I select a value from the "Template" dropdown box, it re-fires the config and hides the combobox. Selecting a value from other combo's in the form seems to do the same thing, but ONLY the ones that are remote calls (from a URL that returns JSON for the combo).

Any fixes for remote combo's "resetting" form configs?

EDIT: All code for ComboBox's. All of these are just rendered inside a FormPanel.

var inventorySelectDropdown = {
    xtype: 'ibwComboLocal',
    fields: ['id', 'name'],
    data: [[1, 'O&O'], [2, 'Network']],
    value: 1, // set to O&O by default
    fieldLabel: 'Inventory'
};

var bulkImportType = {
    xtype: 'ibwComboLocal',
    fields: ['id', 'name'],
    data: [[1, '3rd Party Tag'], [2, 'Image'], [3, 'Template']],
    fieldLabel: 'Type',
    listeners: {
        'select': function(combo, record, index) {
            if (record.get('name') == 'Template') {
                this.bulkImportTemplateCombo.show();
            } else {
                this.bulkImportTemplateCombo.hide();
            }
        }, scope: this
    }
};

var bulkImportTemplate = {
    xtype: 'ibwComboJson',
    hidden: 'true',
    url: 'xxx',
开发者_运维问答    ref: '../bulkImportTemplateCombo',
    root: 'templateList',
    fieldLabel: 'Template'         
};

var vendorDropdownBulk = {
    xtype: 'ibwComboJson',
    url: 'xxx',
    root: 'vendorList',
    fieldLabel: 'Vendor'
};

var bulkImportUploadField = {
    xtype: 'fileuploadfield',
    fieldLabel: 'Select Import File',
    width: 400
};

---

In the 'select' listener's if loop, after the show() function call, add the following statement:

this.bulkImportTemplateCombo.setVisible(true)