Description:
------------
Have only experienced this problem on one server. Fresh php installation, standard php.ini.

Configure line: 
./configure' '--with-mysql=/usr/local/mysql' '--with-apache=/usr/local/src/www/apache_1.3.27' '--with-openssl=/usr' '--enable-track-vars' '--enable-force-cgi-redirect' '--with-gettext' 

Reproduce code:
---------------
$num = 4;
$num = number_format($num, 2);
echo "$num<br>";
$num = 4;
printf ("%.2f", $num);

Expected result:
----------------
4.00
4.00

Actual result:
--------------
0.00
0.00

http://www.yosearch.com/test1.php <- code here
http://www.yosearch.com/test.php <- phpinfo() here