Answered call transferred by queue member drops when goes to voicemail

Similar to http://freepbx.org/trac/ticket/2687

Call flow:
Caller ==> Queue ==> Answered by queue member ==> member transfers call to another extension ==> extension rings, no answer ==> asterisk hangs up

I see "CAME FROM: 575
- Blocking VM cause of key:" show up in the logs.

Log snip:

{noformat}
[Feb 18 17:43:53] DEBUG[6651] app_macro.c: Executed application: GotoIf
[Feb 18 17:43:53] WARNING[6651] func_db.c: DB requires an argument, DB(<family>/<key>)
[Feb 18 17:43:53] VERBOSE[6651] logger.c: – Executing [s@macro-vm:4] NoOp("SIP/8.x.x.146-009652b0", "CAME FROM: 565 - Blocking VM cause of key: ") in new stack
[Feb 18 17:43:53] DEBUG[6651] app_macro.c: Executed application: Noop
[Feb 18 17:43:53] DEBUG[6651] app_macro.c: Executed application: Macro
[Feb 18 17:43:53] VERBOSE[6651] logger.c: – Executing [8954@from-internal:2] Hangup("SIP/8.x.x.146-009652b0", "") in new stack
[Feb 18 17:43:53] VERBOSE[6651] logger.c: == Spawn extension (from-internal, 8954, 2) exited non-zero on 'SIP/8.x.x.146-009652b0'{noformat}

I think that this line:

{noformat}
Feb 18 17:43:53] WARNING[6651] func_db.c: DB requires an argument, DB(<family>/<key>){noformat}

may be it trying to delete the BLOCKVM flag but a typo/bug is preventing it from doing that.

I hope this is helpful, it is difficult for me to get log snips. This system has such high call volume that we have to set verbosity to 0 or the disk activity causes voice quality problems.