Call pickup issue

I have VoicePulse Connect as my VoIP/PSTN termination and am using it in tandem with Trixbox. The configuration is fairly standard, and am having no problems other than a few annoyances here and there.

When I make a call and someone picks up on the other end, there are no problems. However, if I were to make a call and after a few rings a voicemail box picks up, the first few words of the message are always cut off. It doesn’t matter who I’m calling, or whether it goes directly to voicemail or not. Every time, I lose the first few words of the recorded message. It’s almost as if Asterisk is taken by surprise.

Any ideas? I’ve tried switching codecs with no changed results?