If I try to get TrackInfo for the currently playing track, it doesn't get sent, but logs an error:
[09-08-12 16:11:06.2259] Slim::Web::Cometd::sendHTTPResponse (669) Sending Cometd chunk:
[{"error":"encountered CODE(0xb08eb68), but JSON can only represent references to arrays or hashes at /usr/share/perl5/Slim/Web/Cometd.pm line 638.\n","successful":false}]

This works fine if I request any other track from the current playlist, just not the current one.

My request is:
 {
    channel => "/slim/request",
    data => {
          request  => [
                        "00:04:20:12:3b:42",
                        [
                          "trackinfo",
                          "items",
                          0,
                          100,
                          "menu:menu",
                          "context:playlist",
                          "track_id:7953",
                        ],
                      ],
          response => "/051a4a96/slim/request",
        },
    id => 46,
  },

And the full log entry is attached (this looks like the menu gets built but not sent).

r28114 (I don't believe this, I updated this morning to 2814xx, I believe the reported revision is wrong)