Please help to set up freedigits.com to forward incoming calls to Voxalot

[DTN]

I'd set up the unlocked SR SPA-2102-R and Voxalot basic account as guided in this forum.
The IPKall.com forwards incoming calls to Voxalot fine, but the freedigits.com can not forward incoming calls to Voxalot. When I dial freedigits number, the phone doesn't ring. After few ring tones, I hear the voice mail greeting.
I'd received the Iowa state number with the area code 319-449-XXXX yesterday.
I set up the service provider in Voxalot as follow:

User name: 319449XXXX
Host: proxy.freedigits.net
Port: 5060
Active: Yes
SIP Register: No (I can't set this to "yes". Need premium account.)

I set up forwarding in freedigits.com as follow:

phone1: sip:<my Voxalo ID>@us.voxalot.com

Please help!