I've just installed XOOPS and I am getting PHP notices on all the pages I've checked.

I'm running:

XOOPS 2.2.3 Final on:

Windows XP SP2
XAMPP 1.5.1
Apache 2.2.0
MySQL 5.0.18
PHP 5.1.1

Entering the Home page raises the following notice:

Notice [PHP]: Only variable references should be returned by reference in file C:\Program Files\xampp\htdocs\kernel\blockinstance.php line 111

Loging in as admin raises the following notices:

Notice [PHP]: Object of class XoopsUser could not be converted to int in file C:\Program Files\xampp\htdocs\class\theme.php line 442

Notice [PHP]: Only variable references should be returned by reference in file C:\Program Files\xampp\htdocs\kernel\blockinstance.php line 111

The administration page and sub-pages have the following notice:

Notice [PHP]: Object of class XoopsUser could not be converted to int in file C:\Program Files\xampp\htdocs\class\theme.php line 442