Is it ksh itself that's dumping core or some program called
by the script is dumping core?

If so, look at that program more closely and talk to us.

Quoting collver1@attbi.com (collver1@attbi.com):
> Hi,
> 
> I have a shell script that dumps core whenever I run it.  It is a CPU
> intensive script.  But while watching "top", I never see the script use
> more than 750k of RAM, so I doubt it is running out of memory.
> 
> The error is "Memory fault (core dumped)"
> 
> Could someone give me advice on tracking this down?  I'm going to try
> running it with -x, and then try using ktruss.