Cookies + IE / NT = problems

Hi, I' m working with Apache 1.3.12 and php 3.16 under linux RH6.1 I have a really strange problem ... The function setcookie() does not work with IE5 under windowsNT.( but with Netscape, no problem) --> setcookie("user", $id, time()+1000 ,"/",".mydomain.com", 0); I supposed that my program is right since it works with IE5 with win98 or with Netscape under any OS. I have allowed cookies in my browser, and in the file php3.ini --> magic_quotes_gpc=On ; magic quotes for incoming GET/POST/Cookie data. An other thing : When I have installed Apache 1.3.12 and php 3.16 under WinNT, cookies works perfectly with IE5 under windowsNT. I do not understand the reason and I did not find any solution on the web. Have you met this problem ? and if yes, How have you resolved it ? In advance, thank you. Regards, Ludovic.