but with higher values its working fine on other serevrs and localhost as well. just on one server im having this problem.
i hired a programmer from ScriptLance to fix this problem and he referred me to http://pear.php.net/bugs/bug.php?id=6159 and asked to update server cvs for php module. which was updated.
MCrypt was updated too.
it didnt work even after recompiling apache and php...