Symptom: There is some issue with iPeng and the "On Spotify" menu.
The reason seems to be that iPeng uses "contextmenu" to call the initial context menu for an artist or album (for backwards compatibility) while SqueezePlay does not (in 7.6).

SqueezePlay fetches this as the context menu:
 
[11-07-27 23:20:30.3683] Slim::Web::Cometd::handler (149) Cometd request (10.0.0.4:34582): [
  {
    channel => "/slim/request",
    data => {
          request  => [
                        "00:04:20:22:00:c0",
                        [
                          "artistinfo",
                          "items",
                          0,
                          200,
                          "xmlBrowseInterimCM:1",
                          "menu:1",
                          "artist_id:6703",
                          "useContextMenu:1",
                        ],
                      ],
          response => "/a5976bf2/slim/request",
        },
    id => 158,
  },
]
SqueezePad fetches this:
 
[11-07-27 23:25:49.9352] Slim::Web::Cometd::handler (149) Cometd request (192.168.1.101:54128): [
  {
    channel => "/slim/request",
    data => {
          request  => [
                        "00:04:20:06:08:c7",
                        [
                          "artistinfo",
                          "items",
                          0,
                          100,
                          "xmlBrowseInterimCM:1",
                          "artist_id:6703",
                          "menu:1",
                          "useContextMenu:1",
                        ],
                      ],
          response => "/1edf29eb/slim/request",
        },
    id => 16,
  },
]
iPeng fetches this:
 
[11-07-27 23:26:57.4590] Slim::Web::Cometd::handler (149) Cometd request (192.168.1.101:54183): [
  {
    channel => "/slim/request",
    data => {
          request  => [
                        "00:04:20:06:08:c7",
                        [
                          "contextmenu",
                          0,
                          100,
                          "userInterfaceIdiom:iPeng",
                          "menu:artist",
                          "artist_id:6704",
                          "useContextMenu:1",
                        ],
                      ],
          response => "/e7d1939c/slim/request",
        },
    id => 42,
  },
]
This requires the server to pass though additional code to convert from the contextmenu request to an artistinfo request which does not carry forward the connectionID within the server.  The context menu code I added for caching state which is what is needed to make the Spotify plugin (and probably others) work needs this...
 
So needs an iPeng change or a server change....  Server change would probably be something like this:
 
Index: Slim/Control/Queries.pm
===================================================================
--- Slim/Control/Queries.pm     (revision 32886)
+++ Slim/Control/Queries.pm     (working copy)
@@ -4447,8 +4447,10 @@
        if (defined($menu)) {
                # send the command to *info, where * is the param given to the menu command
                my $command = $menu . 'info';
-               $proxiedRequest = Slim::Control::Request::executeRequest( $client, [ $command, 'items', $index, $quantity, @requestParams ] );
-
+               $proxiedRequest = Slim::Control::Request->new( $client->id, [ $command, 'items', $index, $quantity, @requestParams ] );
+               $proxiedRequest->connectionID( $request->connectionID );
+               $proxiedRequest->execute();
+
                # Bug 13744, wrap async requests
                if ( $proxiedRequest->isStatusProcessing ) {
                        $proxiedRequest->callbackFunction( sub {