Periodic-announce-frequency not working as expected?

Hello all.

I’m trying to play a message every 30 seconds in a queue. To do so I’m using the periodic-announce and periodic-announce-frequency parameters.

The sound is playing correctly but for some reason it doesn’t respect the frequency parameter.

For example, if I set the frequency to 20 or 21, the message is played every 20 seconds but if I set the frequency to 22, the message is played every 40 seconds!.

So I can’t play my message every 30 seconds. Am I missing something or it may be a bug?.

I’m using Asterisk 1.2.4.

Thank you.