Upgrade PHP 4.3.4 to PHP 5.0.3 (Windows 2k & IIS5), I recieve a Blank Page and Session errors

Hi, I'm trying to upgrade the PHP version of my dev enviroment. After installing PHP5 I've just recieve a blank page. I activated the error log of PHP and recieve a couple of errors like this one: [09-Feb-2005 13:38:20] PHP Notice: Undefined index: sitedesc in c:\Inetpub\wwwroot\Inpae\admin\lib\headerFooter.php on line 40 All related to $_SESSION, like the values are not set (sitedesc is one of the indexes of the variable $_SESSION) I have in the session values of the php.ini this? session Session Support enabled Registered save handlers files user sqlite Registered serializer handlers php php_binary wddx Directive Local Value Master Value session.auto_start Off Off session.bug_compat_42 On On session.bug_compat_warn On On session.cache_expire 180 180 session.cache_limiter nocache nocache session.cookie_domain no value no value session.cookie_lifetime 0 0 session.cookie_path / / session.cookie_secure Off Off session.entropy_file no value no value session.entropy_length 0 0 session.gc_divisor 1000 1000 session.gc_maxlifetime 1440 1440 session.gc_probability 1 1 session.hash_bits_per_character 5 5 session.hash_function 0 0 session.name PHPSESSID PHPSESSID session.referer_check no value no value session.save_handler files files session.save_path c:\PHP\sessiondata\ c:\PHP\sessiondata\ session.serialize_handler php php session.use_cookies On On session.use_only_cookies Off Off session.use_trans_sid 0 0 Can anyone help me? I've tryed also the CGI and the ISAPI configuration, both give me the same problem. Also I tried to debug my PHP with Zend and recieve this errors: Notice: C:\Inetpub\wwwroot\Inpae\lib\include.php line 15 - Undefined index: SCRIPT_NAME Notice: C:\Inetpub\wwwroot\Inpae\lib\include.php line 15 - Undefined index: PATH_TRANSLATED Debug Warning: C:\Inetpub\wwwroot\Inpae\lib\include.php line 3 - main(/config.php) [<a href='function.main'>function.main</a>]: failed to open stream: No such file or directory Compile Error: C:\Inetpub\wwwroot\Inpae\lib\include.php line 3 - main() [<a href='function.require'>function.require</a>]: Failed opening required '/config.php' (include_path='.;c:\php5\pear') Thanks a lot Fabian