[Zope] Auto restart (at Zope's own initiative !!!)

This happened on my newly installed Zope 2.5.0 (on debian box) I don't remember having done something special (just when browsing folders through the ZMI) and working alone on this server. Here is the console log... (nothing special before) 2002-01-28T20:00:31 ERROR(200) zdaemon zdaemon: Mon Jan 28 21:00:31 2002: Aiieee! 2664 exited with error code: 11 ------ 2002-01-28T20:00:31 INFO(0) zdaemon zdaemon: Mon Jan 28 21:00:31 2002: Houston, we have forked ------ (start log as usual after) Any hint ?