Asterisk, Recording audio through a provider with VAD

I have an application which records audio using an agi script: $AGI->exec('MixMonitor',"[login to view URL]"); The problem is that if i am using a VoIP provider which has voice activity detection turned on MixMonitor will not record any silence. This means that even though the recorded audio was 60 seconds long, MixMonitor only got 55 seconds because silence was not recorded. I am looking for a solution that will record all audio and silence. I am using asterisk 1.6.0.17 and recordings must be in wav format. I also need to be able to call the command to record from an agi script (developed in perl). I can provide access to a server and provider where the problem is happening along with numbers needed for testing. Thanks.