Popup / Dialog positioning for a subapplication

Question

We are loading sub applications into our parent application using separate ApplicationDomains but using the same Security Domain.
When we use an Alert, the alert is centered on the sub application, not the parent application.  Is there any way to get a Popup to center on the parent application instead?
We have a widgets style dashboard and some of the widgets are really small.  So, when they do a popup, it is often off the edge of the screen.
We copied this code from Alert.as to put in our dialog class, as it seemed like it was on the right track, but it always seems to go into the "else"
        if (!this._parentSprite)
                //Below for Flex 4 - also taken from Alert.as.            
            var sm:ISystemManager = ISystemManager(FlexGlobals.topLevelApplication.systemManager);
    // no types so no dependencies
    var mp:Object = sm.getImplementation("mx.managers.IMarshallPlanSystemManager");
    if (mp && mp.useSWFBridge()) {
                this._parentSprite = Sprite(sm.getSandboxRoot());
            else {
                this._parentSprite = Sprite(FlexGlobals.topLevelApplication);
We just want a way to use the parent application as the centering.  Thanks in advance for any help.
Irv

Answer 1

Also, when using getSandboxRoot(), we get the following error:
stack trace=TypeError: Error #1009: Cannot access a property or method of a null object reference.
[trace] at mx.accessibility::AccImpl$/http://www.adobe.com/2006/flex/mx/internal::getDefinition()[E:\dev\4.x\frameworks\projects \framework\src\mx\accessibility\AccImpl.as:248]
[trace] at mx.accessibility::UIComponentAccProps()[E:\dev\4.x\frameworks\projects\framework\src\mx\a ccessibility\UIComponentAccProps.as:120]
[trace] at mx.accessibility::UIComponentAccProps$/http://www.adobe.com/2006/flex/mx/internal::createAccessibilityImplementation()[E:\dev\4.x \frameworks\projects\framework\src\mx\accessibility\UIComponentAccProps.as:76]
[trace] at mx.core::UIComponent/initializeAccessibility()[E:\dev\4.x\frameworks\projects\framework\s rc\mx\core\UIComponent.as:7400]
[trace] at mx.core::UIComponent/initialize()[E:\dev\4.x\frameworks\projects\framework\src\mx\core\UI Component.as:7355]
[trace] at mx.core::Container/initialize()[E:\dev\4.x\frameworks\projects\framework\src\mx\core\Cont ainer.as:3129]
[trace] at mx.managers.systemClasses::ChildManager/childAdded()[E:\dev\4.x\frameworks\projects\frame work\src\mx\managers\systemClasses\ChildManager.as:189]
[trace] at mx.managers::SystemManager/http://www.adobe.com/2006/flex/mx/internal::rawChildren_addChildAt()[E:\dev\4.x\frameworks \projects\framework\src\mx\managers\SystemManager.as:1963]
[trace] at mx.managers::SystemManager/addChildAt()[E:\dev\4.x\frameworks\projects\framework\src\mx\m anagers\SystemManager.as:1595]
[trace] at mx.managers::SystemManager/addChild()[E:\dev\4.x\frameworks\projects\framework\src\mx\man agers\SystemManager.as:1578]
[trace] at mx.managers::PopUpManagerImpl/addPopUp()[C:\view\isalisbu_olr_ss2\png\apps\olr\ui\src\mai n\flex\mx\managers\PopUpManagerImpl.as:346]
[trace] at mx.managers::PopUpManager$/addPopUp()[E:\dev\4.x\frameworks\projects\framework\src\mx\man agers\PopUpManager.as:193]
[trace] at com.paychex.framework.controls::Dialog/show()[C:\view\isalisbu_olr_ss2\png\apps\olr\ui\sr c\main\flex\com\paychex\framework\controls\Dialog.as:75]
[trace] at com.paychex.framework.containers::ActionAreaDialog/show()[N:\Hudson\workspace\PNG_UIFrame work_v03_RC\hapnv022_PNG_UIFramework_v03_RC\soa_suite\png\framework\flex\ui-component\src\ com\paychex\framework\containers\ActionAreaDialog.as:61]
[trace] at Function/<anonymous>()[N:\Hudson\workspace\PNG_UIFramework_v03_RC\hapnv022_PNG_UIFramewor k_v03_RC\soa_suite\png\framework\flex\ui-bulb\src\com\paychex\framework\bulbs\DialogContro llerBulb.as:297]
[trace] at Function/http://adobe.com/AS3/2006/builtin::call()
[trace] at Function/<anonymous>()[N:\Hudson\workspace\PNG_UIFramework_v03_RC\hapnv022_PNG_UIFramewor k_v03_RC\soa_suite\png\framework\flex\ui-bulb\src\com\paychex\framework\bulbcore\DynamicBu lbHelper.as:61]
[trace] at Function/http://adobe.com/AS3/2006/builtin::call()
[trace] at Function/<anonymous>()[N:\Hudson\workspace\PNG_UIFramework_v03_RC\hapnv022_PNG_UIFramewor k_v03_RC\soa_suite\png\framework\flex\ui-bulb\src\com\paychex\framework\bulbcore\Juicer.as :975]
[trace] at Function/http://adobe.com/AS3/2006/builtin::call()
[trace] at WiringHelper/wiringLoadSuccess()[N:\Hudson\workspace\PNG_UIFramework_v03_RC\hapnv022_PNG_ UIFramework_v03_RC\soa_suite\png\framework\flex\ui-bulb\src\com\paychex\framework\bulbcore \WiringHelper.as:42]
[trace] at Function/http://adobe.com/AS3/2006/builtin::apply()
[trace] at com.paychex.framework.util::DelayedInvoker/timerHandler()[N:\Hudson\workspace\PNG_UIFrame work_v03_RC\hapnv022_PNG_UIFramework_v03_RC\soa_suite\png\framework\flex\ui-core\src\com\p aychex\framework\util\DelayedInvoker.as:46]
[trace] at flash.utils::Timer/_timerDispatch()
[trace]
In watching the code from alert, it never gets into the code that uses getSandboxRoot.  We are using the same security domain (trusted code) so we are not a sandboxed app, we are a mutli-versioned app (load for compatiblity / different application domain)
I'll work on a snippet of code that is easier to discuss that demonstrates the problem.