Noice canceletion in two separate flash players

Hello!

In our web app (Live chat) we are using two flash objects on the same page (first for sending video+audio from streamer, second for recieving it from another streamer). In both objects we have the same configuration about video and audio. All was good but some time ago we noticed that the echo canceletion just stoped working! So all our users now have to use headfones, coz they can't chat without it - noises, echo... What r we doing wrong? Or where is the problem?

We have:

SoundCodec('nellymoser')

BufferLength(0)

SoundEnhancedMode('full_duplex')