Voicemail Problems

[All4Fun]

I'm a Voxalot Basic (free) user and am currently doing SIP URI forwarding from voip.ms to Voxalot. The ATA that I'm using is Linksys RTP300 (very similar voip configuration to a pap2).

The problem that I'm having is that receiving voicemail to a Voxalot mailbox is inconsistent. Sometimes it works and sometimes it doesn't. The majority of the time it doesn't work as expected. This is what I'm experiencing:

1. Inbound calls don't get transferred to voicemail. Rings forever.
2. Inbound calls get transferred to "dead air". No beep or message but gets transferred to voicemail.

When it works, it works fine but it's not consistent enough to be considered acceptable.

I've turned off voicemail at voip.ms. Also, since I'm doing sip uri forwarding, I'm not expecting that this would play a role anyway.

My Voxalot voicemail is set at a 20 second duration (from default 27).

Any ideas on how I can solve this problem? Thanks.