I upgraded my 11/01/99 CVS build with the RC4 build (totally starting over from scratch), and started having some very strange problems when I started manipulating strings.  Basically I have a string that is used for 'flags', (i.e. position 1 has a flag of A, position 2 B, etc.).  Normally, I change these flags from a webpage by recursing through an array and changing individual characters.... but suddenly it stopped working, and has started segmentation faulting ... here's a code segment of the problem code:

$inarray = array(1=>"A",2=>"B",3=>"C"); // etc...

$string = "A--DF--S--DS---C";

while (list($key,$val) = each($inarray)) {
       echo "PRE: $string<br>";
        $string[$key] = $val;
       echo "POST: $string<p>";
}

...

this works for about 2 iterations, then we have major memory munging, and $string turns into a bunch of garbage.. (even a Yen symbol or three) after 2 more iterations, the Apache child process dies.

I tried doing a few different things, including converting $string to an array first, then doing a individual element replace... but then I discovered that a reset($inarray) also segfaulted things.