Bug in last php version

Dear sir, Now I using the php 5.2.3 with IIS on windows 2003, all scripts is not working in this version where I'm detect the php is save the function declaration in cash, you can use the code: <? function test(){ return 2; } echo '<form name="FormName" action="" method="post"> <input type="submit" value="Send"> </form>'; ?> please click on submit many time, you must have the msg: Fatal error: Cannot redeclare test() (previously declared in C:\accounts\panela\tmp\bug.php:2) in C:\accounts\panela\tmp\index.php on line 2 please give me how can I solve this problem? Thanks Ramy