I have a 3cx v12.x box running on a Windows 7 pro 64bit hyper-v vm with 4gb ram, the vm host is running server 2012 r2, it's a dell pe t630, calls come in thru a Patton SmartNode SN4912/JO/RUI gateway that basically takes pots lines and turns them into sip trunks for the phone system. Voicemails intermittently come in blank, as in silent. It may be a 2 minute voicemail, but it's 2 min's of silence. This occurs whether I check the voicemail directly on the phone or as a vmail 2 email attachment. I believe I've even checked in the vmail folder on 3cx and the actual wav file is blank too. Any thoughts on how to resolve this?