GOautodial Open Source Omni-channel Contact Center Suite

hi,
is happening to me for a week on both servers I have with goautodial 2.1 which falls during the phone call recording, I have a 20% of calls that fall when the registry, I can not understand the problem because I have no time for the same sample after 1 other minute after 4 minutes and so on.
What can be the problem? already rule out the problem of what processor and ram space on the harddisk. because both servers are powerful enough and until a week ago they worked fine.