The keyring unlock is done using a fallback dialogue, when using autologin, instead of being done in the shell.

Stef thought this patch could help (making sure the keyring handling is done before the telepathy client, which might trigger the password dialogue, is launched):
diff --git a/js/ui/sessionMode.js b/js/ui/sessionMode.js
index 808109a..7f124fd 100644
--- a/js/ui/sessionMode.js
+++ b/js/ui/sessionMode.js
@@ -91,8 +91,8 @@ const _modes = {
         isLocked: false,
         isPrimary: true,
         unlockDialog: imports.ui.unlockDialog.UnlockDialog,
-        components: ['networkAgent', 'polkitAgent', 'telepathyClient',
-                     'keyring', 'recorder', 'autorunManager', 'automountManager'],
+        components: ['keyring', 'networkAgent', 'polkitAgent', 'telepathyClient',
+                     'recorder', 'autorunManager', 'automountManager'],
         panel: {
             left: ['activities', 'appMenu'],
             center: ['dateMenu'],