Premature playing of announcement with A parameter Dial cmd

I’m using the A parameter to have an announcement played to the called party when he or she picks up the phone.

Dial(SIP/3120xxxxxxx/${OUTBOUND},40,A(/var/lib/asterisk/sounds/aankondiging))

I make use of a SIP provider. The announcement starts before the other party picks up the phone so he or she misses (part of) the announcement. I have tested it with sip accounts of two different sip providers and they both have the problem of premature playing of the announcement

Is this an issue with the A parameter in Asterisk or is this to blame to the sip providers who send an 200 OK sip message while the called party haven’t picked up the phone yet. I can hardly imagine that it is Asterisk that is to blame because the A paramter is part of Asterisk since the 0.7 cvs version of Asterisk.

If you have the A parameter working well with a sip account please let me know. if You have any suggestions or ideas please share them with me. Thanks in advance.