air.swf getApplicationVersion() not calling back

I am trying to use air.swf fromhttp://airdownload.adobe.com/air/browserapi per the Adobe documentation to detect if an air application is already installed. I'm using getApplicationVersion but the callback function is never called. launchApplication() and installApplication() work fine.
The code looks like this:

_air.getApplicationVersion(appID, pubID, versionDetectCallback);
function versionDetectCallback(version:String):void { do stuff }

VersionDetectCallback() is never called. I de-compiled the air.swf and ran the code directly to try and figure out what's failing. But I get the same result. I can see the timer on the LocalConnection endpoint timing out after 5 seconds. I just can't figure out why the appinstaller is not calling back. The actual call (taken from the decompiled swf) looks like this:

airappinstaller = new ProductManager("airappinstaller");
var launchArgs:Array;
launchArgs = ["-isinstalled", appID, pubID, "adobe.com" + ":" + lcName, "onApplicationVersion"];
airappinstaller.launch(launchArgs.join(" "));

where onApplicationVersion is the endpoint callback function and lcName is the LocalConnection name.

It doesn't matter if I make the call from the Loader Init event or in a button click the callback function is never called. I am using Flash CS3.