Memory corruption bug

Hi there, I've been running a PHP server with Wordpress for a good while now, when I stumbled upon a problem uploading some posts, where the script would enter a loop and run till it crashed, running out of process memory. I managed to create a test case based on Wordpress's code and my HTML content, then narrowed down the loop and variables that are being (apparently) corrupted in some way: The relevant variables are $i and $l, which at the time the code blows up, store 68 and 71, as integers. These are summed as a parameter to substr() in the loop, which gets a float instead of the value "139". The rest of the code runs a $text var and a $newtext var, upon which the force_balance_tags() function from formatting.php iterates. These are the dumps at the time when the code does bad things: $i: int(68) $l: int(71) $i + $l: float(9.7837007760303E+18) Only the sum gives wrong results, the other operations like subtraction and multiplication produce accurate results. This only happens in this iteration of the loop. Previously, I managed to circumvent the bug by copying the $text variable into another variable, just before the line with the two substr() operations on $text, which was were the code was having problems. After a while of successfully posting my edits without knowing anything more about the problem, I noticed this might be a more widespread problem when Wordpress started producing garbage HTML on some strings, in other places, and went looking deeper. I tried to find a way to maybe debug this but have no idea of how to look at process memory in php, or what to look for. I have a test case to submit but am unsure if I should file a bug or if I'm posting in the right mailing list at all. Any help is greatly appreciateed. Best regards, Tiago Marques