Thanks Ross,
I'll have to hope that a PHP upgrade will solve the problem - I'm using 4.06 right now.
In the meantime, it looks like my server's 256 Mb of memory is getting a run for its money, and there's periodic use of the swap file (under perl). I think I'm going to switch to PHP again, just to monitor memory utilization. As each child process carries a copy of PHP with it, it's possible that PHP is being much more demanding of memory, causing the system to slow down as it starts swapping to disk, and in turn causing the mySQL/PHP combo to misbehave, lock processes in an attempt to recover from the slowdown, etc.
That's my best theory so far. I'll start by buying some more memory.
Regards,
Max
