Problem with Asterisk (Trixbox 1.1.0) Background() function

Hi there

I am having troubles with the Background function on my Trixbox.
I am using Trixbox Version 1.1.0
Even the simple IVR menu below won?t work. The background function does not recognize my inputs.

In the [custom-mainmenu], the call gets answered then it goes till the second Background( ) . Apart from not going till the s,8 step, I have another problem: even if I press 1, it does not playback the file.

Does anyone have an idea of what I could be making wrong. Should I try a version of Asterisk instead of Trixbox? Could this be a problem wth the Voip-provider? Thank you for any help.

exten => s,1,Answer
exten => s,2,Background(/var/lib/asterisk/sounds/quantidade)
exten => s,3,Wait(2)
exten => s,4,Background(/var/lib/asterisk/sounds/alimento)
exten => s,5,Wait(2)
exten => s,6,Background(/var/lib/asterisk/sounds/quantidade)
exten => s,7,Wait(2)
exten => s,8,Hangup
; Tech Support
exten => 1,1,Playback(benvindo)
exten => 1,2,Hangup