UpdatePanelAnimationExtender ScriptAction Running on Postback

I have an UpdatePanel which includes some buttons which trigger callbacks and others that trigger postbacks.  The buttons that trigger postbacks are added to the <Triggers> collection. 

<asp:UpdatePanel runat="server" ID="upUpdatePanel"><Triggers><asp:PostBackTrigger ControlID="butStage4Save" /><asp:PostBackTrigger ControlID="butLoadMap" /></Triggers><ContentTemplate>
     ....

I also have an UpdatePanelAnimationExtender which executes a JavaScript function via ScriptAction:

<%--This is what causes the 'updating' animination to run when the specified Update Panel is updating or has updated
The javascript functions that are called are at the top of this page--%><act:UpdatePanelAnimationExtender ID="upae" BehaviorID="animation" runat="server" TargetControlID="upUpdatePanel"><Animations><OnUpdating><Parallel duration="0"><ScriptAction Script="onUpdating();" />  <FadeOut minimumOpacity=".5" /></Parallel></OnUpdating><OnUpdated><Parallel duration="0"><FadeIn minimumOpacity=".5" /><ScriptAction Script="onUpdated();" /> </Parallel> </OnUpdated></Animations></act:UpdatePanelAnimationExtender>

The onUpdating() function runs an animation.  The animation works great during an AJAX request, but my problem is that it also runs when issue a Postback via the Buttons in my <Triggers> collection.  I don't want the user to see the animation during a Postback.

Is there any way to only call the ScriptAction function during a callback, but not a postback?  Or to check some variable in the onUpdating() function to ignore the postbacks?

Thanks.