Every 60-90 days, we seem to have a problem with one of one of our PBXs: we have dropped calls, can't get dialtone, or users are unable to make internal or external calls (or both) - sometimes all of the problems above at the same time. The only way we've been able to fix the problem so far is to re-initialize that PBX and two others that it's connected to (at other sites). The only error messages that I've seen are minor: ERR5132 and ERR5142, TRK160 and TRK166, BUG4001, BUG1359, BUG1389, BUG1361, and MSDL0304. Is this a timing problem? A database corruption problem?