How to remove the Alert Info header in 1.4

Hi,

I have a new problem since a updated to Asterisk 1.4. I’m using Polycom phone with distictive ringtone using the alert-info header.

With 1.2 I used to do the following :

Set(_ALERT_INFO=info=Custom 1) to set the distinctive ringtone.

And to remove it I used to do :

Set(_ALERT_INFO=info=)

That way I could set and remove the distinctive ringtone easly. Since I updated to 1.4, I had to replace with Sipaddheader(Alert-Info:Custom 1). However, not I’m unable to remove the header to “disable” the distinctive ringtone. This is not working :

Sipaddheader(Alert-Info:)

Any idea ?

Thx