To my guess with php orphans collection you killing suexec daemons.
Usually suexec daemon process gone away after
2013-06-11 07:10:03.185 [STDERR] [Tue Jun 11 07:10:03 2013
] Possible runaway process, PPID: 21885, PID: 21861, reqCount: 1, process time: 161, checkpoint time: 161, start time: 161
But I have no details yet. Do you think it is safe to switch back to 4.2.2 with phps built for new lsapi?