Non active PML domains

Hi,

I have made a model for thin film bulk acoustic resonator. I have problem with the PML domains. my model has two physics: Solid mechanics for PML domins and Piezoelectric devices for remaining. when I run computation, no calculation happens in the PML domains like there is no such domains.
I tried to follow the "Thin Film BAW composit resonator sample from show cases in the COMSOL file but no improvement .
By the way, even when I open t"Thin Film BAW composit resonator sample from show cases in the COMSOL website in v4.2a the same problem happens.
I have a jpeg picture of what result look like.

Would you please give some advice?

Best Regards,
Ramin,