asterisk users - Jan 2009 - Voicetronix Openswitch 12 + echo problem

Hi all,

    Anyone has this card installed and configured without echos between SIP 
and VPB channels ?
    I have 2 Openswitch cards and i always have echo problems in Analog 
Lines.
    If i operated SIP through SIP i have no echos, but if i try to operate 
SIP through VPB there is alot of echos in line.
    I played with Input and Output gain in PAP2 settings without luck.
    Any help would be appreciate !
    Thanks in advance,

    Gleidson Antonio Henriques