[AC-2185] WebView problem with Alloy on iPad within SplitWindow

I've been having some problems with a WebView in my first Alloy application. Everything works fine on the iPhone (simulator and device). It's only on the iPad that I have a problem - the difference in the code being that I am using a SplitWindow for the iPad. The WebView work fine in the iPad simulator but on the device itself it is very sluggish and doesn't respond to clicks very well. Sometimes it results in a crash. Simple Alloy example: Index.js

$.index.open();

Index.xml

<Alloy>
    <SplitWindow id="index" showMasterInPortrait = "true" formFactor="tablet" platform="ios">
        <Require src="master"/>
        <Require src="detail"/>
   </SplitWindow>
</Alloy>

master.xml

<Alloy>
    <Window>
    </Window>
</Alloy>

detail.xml

<Alloy>
    <Window title = "Detail">
            <Require src="webViewWin"/>
    </Window>
</Alloy>

webViewWin.xml

<Alloy>
    <WebView url = "http://www.bbc.co.uk" id="webView"/>
</Alloy>

Creating a very basic equivalent application using the Classic Titanium master-detail template works fine, the webview is fast and responsive and works ok so I can only assume this is alloy related?