2 weird problems to be solved

HI, our new upgraded asterisk (1.4.9) comes with some weird issues.

  1. “Directory command” works fine to locate the name, however, IVR plays the greeting or letter-by-letter randomly. Sometimes it works normally, sometimes it won’t play the voice even I saw it found the right guy on Asterisk console.

  2. when extension users pick up a call, the caller party won’t be able to hear what extension users say for around 2-3 seconds when extension users can hear what caller says.

Is there anyone with any idea what could be wrong?

Many thanks.