Jeff is correct and if I'd thought about it at the time I'd have realised that g-v-m is only responding to the "new media" signal from HAL, which has to wait for the drive to spin up. One idea is that maybe HAL should emit a pre-device-added signal so that g-v-m can pop up a notification area icon saying that something has been inserted and it's being probed.

However I'm not a great fan of Christian's proposal. Personally I'd prefer we invented some MIME types, i.e. application/x-device-cdda for "can play audio CDs" and g-v-m can then display lists of applications based on the MIME type keys, and also use the startup notification information in the .desktop files.