Problem with Android 4 StageWebView cutting off/covering up buttons on same View

So I'm trying to pull off something similar to the example here: http://cookbooks.adobe.com/post_Create_a_basic_web_browser_with_StageWebView-18850.html. Basically, a native browser view with a few Flex controls over top. Problem is, I've been running into a lot of display problems on Android 4 devices specifically. As far as I can tell, the StageWebView seems to be preventing the button overhead from being rendered in part or *at all* - as in, the button doesn't show up at all. It's just black.

See for yourselves. Here's a screenshot (the test page has a yellow background):

If I touch the screen or the web view, the button will (usually) abruptly show up above the page, where it's supposed to be:

Anyone else seen anything like this before? Any ideas what it could be?

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Additional information for those who might want it:

- Project is being developed in Flash Builder 4.6 with the 4.6 SDK. Screenshots are from a Google Nexus 7 tablet (Android version 4.1.2, Adobe AIR version 3.4.0.254).

- the view in this case is an ActionScript class extending View with a skin. Here's the relevant code:

[SkinState("ready")]
[SkinState("loading")]
public class LogInWebView extends View
{
          [SkinPart(required="false")]
          public var previousButton:Button;
          private var browser:StageWebView;
          private var url:String;
          private var isFirstPageLoaded:Boolean;
          public function LogInWebView()
          {
                    super();
                    isFirstPageLoaded = false;
          }
          override public function set data(value:Object):void {
                    url = value.url;
                    invalidateProperties();
          }
          // protected functions
          override protected function createChildren():void {
                    super.createChildren();
                    if (url) {
                              browser = new StageWebView();
                              browser.viewPort = new Rectangle(0, 0, stage.stageWidth, stage.stageHeight);
                              browser.addEventListener(Event.COMPLETE, onFirstPageLoaded, false, 0, true);
                              browser.loadURL(url);
                    }
          }
          override protected function partAdded(partName:String, instance:Object):void {
                    super.partAdded(partName, instance);
                    if (instance === previousButton) {
                              previousButton.addEventListener(MouseEvent.CLICK, onPreviousButtonClick, false, 0, true);
                              if (browser) {
                                        browser.viewPort = new Rectangle(0, previousButton.height, stage.stageWidth, stage.stageHeight-previousButton.height);
                              }
                    }
          }
          override protected function commitProperties():void {
                    if (isFirstPageLoaded && currentState != "ready" && browser) {
                              // display StageWebView now that it's loaded
                              skin.currentState = "ready";
                              browser.stage = this.stage;
                    } else if (currentState != "loading") {
                              skin.currentState = "loading";
                    }
                    super.commitProperties();
          }
          // event listeners
          private function onFirstPageLoaded(event:Event):void
          {
                    browser.removeEventListener(Event.COMPLETE, onFirstPageLoaded);
                    isFirstPageLoaded = true;
                    invalidateProperties();
          }

- note: the button ONLY appears in state "ready" - it's not in state "loading."

Your thoughts?