Queue Music on Hold Class settings not honored when the queue is used as Failover Destination

I'm trying to accomplish this setup (http://www.freepbx.org/forum/freepbx/users/first-ring-then-music-on-hold):

This is the setup:

Queue: 1001 (MainQueue)
Queue: 1002 (MainQueue Failover)

1) an external caller call the main corporate number

2) the call is redirected to queue 1001 and the customer hear RING tone for 15 seconds:
Music on Hold Class: Default (Ring Only)
Join Announcement: None

3) after 15 seconds, if no one answer the call, it's redirected to queue 1002 as failover
Music on Hold Class: Default (MoH Only)
Join Announcement: Welcome.wav

4) The caller hear the Welcome Message, but after this it hear the RING TONE and not the Music on Hold

Notes:

1) If i set as direct destination of inbound route the queue 1002, I hear the MoH.

2) If i configure a Ring Group with MoH as failover destination of queue 1001, I can hear the MoH

Tested against Asterisk 1.8.23.1 32bit and FreePBX 2.11 (updated to 20130912)

Best Regards