Description:
------------
cyclyng (with for and while) from 'A' to 'Z' the cycle doesn't stop to 'Z' but continue, passing from 'AA', 'till 'YZ'

ps.
the bug was submitted here too
<http://bugs.php.net/bug.php?id=15597> 
on date: 18 Feb 2002
php version: 4.1.1
and is still present in php4.4.2 and in php5.2-200606091630

Reproduce code:
---------------
<?
for($i='A'; $i<='Z'; $i++)
        echo $i . ", ";
?>

Expected result:
----------------
A, B, C, ..., Z

Actual result:
--------------
A, B, C, ..., Z, AA, AB, AC, ..., YW, YX, YY, YZ

i can't post a backtrace because the program exit normally, without a crash :-(