Audio artifacts using Asterisk 1.4.21 and Zaptel

I just upgraded my Zaptel and Asterisk as mentioned in topic. Occasionally when I’m on a call, when I start talking, there will be a scratchy sound that seems to happen in sync with my voice. This did not happen before when I was using Asterisk 1.2.25 and a 1.2 version of Zaptel.

I’m using ECHO_CAN_MG2 and AGGRESSIVE_SUPPRESOR in zconfig.h, but that doesn’t seen to help.

I have a PRI coming in to a TE120P card, running FC7 with kernel