Hi, I am trying to understand odd(different) behavior of the header function under two different environments. Here is the code which I am trying to execute from two different servers <? header ("Set-Cookie: c1=value1;path=/; domain=.domain.com"); header ("Set-Cookie: c2=value2;path=/; domain=.domain.com"); ?> When executed from server1(OS X), both cookies are set in browser, but when executed from server2(Linux), only the second cookie is set. server1 and server2 are running different OS and php version as below. I know I could add $replace=false option on the Linux server, but I am trying to understand the different behavior of header() function on these two servers. Any thoughts? server1 - OS X ---------------------------------------------- PHP Version 5.2.4 System Darwin host2.domain.com 8.8.4 Darwin Kernel Version 8.8.4: Sun Oct 29 15:26:54 PST 2006; root:xnu-792.16.4.obj~1/RELEASE_I386 i386 ---------------------------------------------- server2 - Linux ---------------------------------------------- PHP Version 5.3.5 System Linux host1.domain.com 2.6.18-164.15.1.0.1.el5 #1 SMP Wed Mar 17 01:10:06 EDT 2010 x86_64 -Rao