you don't know how difficult is it, everything here in library relies on 
windows - and I can not do anything but show them how could it be done 
better and cheaper with linux

I know all these things about security in win98 - why 1.3 ? - hmm, I 
found some binary on disk and never needed to install anything higher, 
until now I comfortably used apache 1.3.1 for MySQL, PHP 4.3.2, swish-e 
2.2.3, and as I have already said, production machine is Debian

 >
 > 1.3.1!  That's something like seven years old.  Why are you bothering
 > with Windows 98?  That said, I have ran swish.cgi on my Windows
 > machine which is running plain old Windows 98 and not seen these
 > errors.  Maybe I wasn't looking close enough.

so, your win98 works?! I will try to remove PHP dll, stop rewriting ...

 >
 >>correct -> swish_binary => '/romca/swish5/swish-e.exe',        # OK
 >>           swish_binary => '../../swish-e.exe'
 >>wrong -> swish_binary => 'c:/romca/swish5/swish-e.exe',
 >
 >
 > I can't believe that's true.

anybody else having windows 98 and willing to try it?

 >
 > I can only find this message in apache_1.3.29/src/main/alloc.c, but I
 > can't pretend to understand what's happening at that point in the
 > code without running it in a debugger on Windows.

so, how do I do that?

 > Why would printing to stderr cause problem?

Printing STDERR is not the problem, problem arises when the script tries 
to Dump certain parts of the "results" hash
 >
 >
 >
 >>when I kill the child manually, apache writes some parts of dumped
 >>structure, mostly swish-e header, and it is apparent that there are some
 >>results
 >
 >
 > Is Windows buffering stderr?
 >
 >
 >>does anyone know why exec is called?
 >
 >
 > exec() has to be called to run CGI scripts, generally.  I'm not sure
 > that the message you are seeing is specifically related to calling
 > exec() at that point.

probably not, in process list there is perl interpreter listed though - 
as soon as script finish, "perl" is gone

 >
 > What I would do it this situation is write a small CGI script and see
 > if you see the errors -- somethings like
 >
 >   #!/bin/perl -w
 >   use strict;
 >   print "Content-type: text/plain\n\nHello World!\n";

I already tried, this is OK.

 >
 > Then I'd likely throw the Windows machine out the window.
 >

first, find the problem, then, solve the problem - that seems right ;)