You said:

In my system, it works if I have fewer variables set in the 'images.lib' file (which normally contains +/- 100 variables set to the HTML IMG tag) yet my client's system was working as of last week. Now, not having made any changes to that system at all, 2 of the 2nd-level menu actions have the same problem.

So, does this mean you have two systems running, and both are showing the same (or basically similar) behavior? And both are running on the same server?

When you say "not having made any changes..." do you mean just the code is unchanged, or that both code and (quantity of) data are unchanged?

Some possible strategies for diagnosis might depend on what type of server it is (windows or unix, with some minor details that might depend on what type of unix) -- though tachyon's advice would apply equally on all systems.

If the server is unix, you could try supplementing the simple "Got to here" messages with some "ps" output -- e.g. with a bsd-style of "ps", the following would give you information on your process size, what memory limits are in effect, and what percentage of memory you're using:

  my $ps = `ps -p $$ -o vsz,rsz,lim,%mem`;
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Write $ps to a log file together with some indicator of where you are in the script, and do this at strategic points. (You'll want to consult the appropriate "ps" man page for correct options and meanings of reported values -- these vary with the unix flavor.) I don't know what sort of method would be available on a windows server to do the same thing, unless a GNU/cygwin/other port of "ps" is available...