Saving map to session doesn't persist?

[Jason Birch]

I've attached an example that I think should save a MapDefinition to the session repository, but a call to MapAgent to render the map comes up with a MgResourceNotFoundException (I think).
 
Is there something that says that MapDefinitions need to be modified to be persisted?  Is there a typo in there somewhere?
 
Jason
-------------- next part --------------
<?php
$extensionDir="C:/Program Files/MapGuideOpenSource/WebServerExtensions/www/";
$viewerDir = $extensionDir . "mapviewerphp/";

include $viewerDir . 'common.php';
include $viewerDir . 'constants.php';

try
{

    MgInitializeWebTier($extensionDir."webconfig.ini");
    $user = new MgUserInformation('Administrator','admin');
    $siteConnection = new MgSiteConnection();
    $siteConnection->Open($user);
    $resourceService = $siteConnection->CreateService (MgServiceType::ResourceService);
    $site = $siteConnection->GetSite();
    $sessionId = $site->CreateSession();
    $user->SetMgSessionId($sessionId);

    //Set up the map to be used in this service
    $resourceID = new MgResourceIdentifier('Library://Samples/Sheboygan/Maps/Sheboygan.MapDefinition');

    //Create a connection to the map
    $map = new MgMap();
    $map->Create($resourceService,$resourceID,'Sheboygan');

    //Save the map into the repository
    $mapId = new MgResourceIdentifier("Session:$sessionId//Sheboygan.". MgResourceType::Map);
    $map->Save($resourceService, $mapId);

    $imageURL= "http://localhost/mapguide/mapagent/mapagent.fcgi" .
    		   "?OPERATION=GETMAPIMAGE&VERSION=1.0.0" .
    		   "&MAPNAME=Sheboygan&LOCALE=en".
    		   "&MAPDEFINITION=Session:".
    		   		$sessionId."//Sheboygan.". MgResourceType::Map .
    		   "&FORMAT=PNG" .
    		   "&SETVIEWCENTERX=103.88257".
    		   "&SETVIEWCENTERY=1.331479".
    		   "&SETVIEWSCALE=4000&SETDISPLAYDPI=100".
    		   "&SETDISPLAYWIDTH=600&SETDISPLAYHEIGHT=600".
    		   "&SESSION=".$sessionId;

    //Output the contents of the request
    header("Content-Type : image/png");
    print file_get_contents($imageURL);

}
catch (MgException $ex)
{
    print "<p>Error: " . $ex->GetMessage() . "<br/>";
    print "Details:" . $ex->GetDetails() . "</p>";
    exit;
}