Displaced REST Map Service in Flex Application

The Scenario:
Recently, I've been doing some development with the ArcGIS API for Flex and ESRI's open-source "Flex Viewer" application. The application includes several widgets which work out-of-the-box. After configuring an application with the basic widgets, I got to the point where I needed extra functionality. In this particular situation, I wanted to be able to load external services (eg. ArcGIS REST or WMS) at runtime. I decided that the most appropriate approach would be to extend the "LayerList" widget.

The Problem:
The modification appeared to be working fine on the development environment. I could load several layers, both REST and WMS, which displayed beautifully.
However, when the flex app was migrated to the production system, I started to notice some issues. The application was fired up, and I loaded an external REST service. It seemed to be working, but when I maximised the window, the data no longer aligned with the basemap. At first I thought that my code had modified the spatial reference for the layer.

The Solution:
After some investigation it occurred to me that the top left corner of the image was in the correct location. I also realised that the returned image was over the correct extent. It turned out that the image which I was requesting was larger than the maximum image size configured for this service. (The default for ArcGIS REST services is 2048x2048 pixels.)

The solution is to modify the service configuration file. On windows servers: C:\arcgis\server\user\cfg\service_directory\service_name.cfg
Simply update the values for MaxImageHeight and MaxImageWidth. I set both of mine to 3072, like so:

<ServerObjectConfiguration>
<Properties>
...
<MaxImageHeight>3072</MaxImageHeight>
<MaxImageWidth>3072</MaxImageWidth>
...
</Properties>
</ServerObjectConfiguration>

I encountered a similar situation with WMS Services, but unlike the REST services, the limited image size (2048x2048) was positioned correctly.
I am assuming that the WMS services are processed more easily because the maximum file size information is visible to the client in the GetCapabilities file. ArcGIS REST services do not expose this information.

More information about ArcGIS Service configuration files can be found here:
http://webhelp.esri.com/arcgisserver/9.3/java/index.htm#cfg_file_service.htm