Queue announcement audio playback is blank at times

I have had this problem cropping up where callers ringing on a route directed at a queue with a file that is played back to them before getting MOH are met with a lengthy blank period before the file is actually heard. Of course this doesn’t sound good for our clients.

– Executing [1000@ext-queues:13] NoOp(“mISDN/2-u67”, “CALLERID(name) is Brett Matthews Mob”) in new stack
– Executing [1000@ext-queues:14] Set(“mISDN/2-u67”, “_RGPREFIX=Queue:”) in new stack
– Executing [1000@ext-queues:15] Set(“mISDN/2-u67”, “CALLERID(name)=Queue:Brett Matthews Mob”) in new stack
– Executing [1000@ext-queues:16] Set(“mISDN/2-u67”, “MONITOR_FILENAME=/var/spool/asterisk/monitor/q1000-20080303-132305-1204510985.85”) in new stack
– Executing [1000@ext-queues:17] Playback(“mISDN/2-u67”, “custom/queuegreet”) in new stack
– <mISDN/2-u67> Playing ‘custom/queuegreet’ (language ‘au’)

The CLI just stops at this point, and nothing is heard during call.

This is happening on both similar setups, with both asterisk 1.4.13, and 1.4.18, with misdn 1.1.6, and 1.1.7.2.

I have double checked for ztdummy, encase it was that. Unsure at this stage if the problem lies within misdn, or asterisk itself. Or freepbx code even.

If I change Freepbx to not play the audio file, and play ring instead, all seems fine. This is not what I would like of course as callers on hold in the queue would get bored of ringing forever.

Any help in this area is most appreciated.

Brett