Upgrade from 1.1rc2 to 1.1rc3 problems: can not register new member

[vhv_alex]

www.joomlaviet.org/forum. [nofollow]
this is my forum url, i have upgraded to 1.1rc3 and i can not register new member ( but i can register new member in the admin panel only ). When i register there is a error message but it do not have a body, just a title like " there was as error "....
Here is my server info
PHP: 4.3.11
Windows NT
Microsoft-IIS/6.0

Thank you in advance

[vhv_alex]

I found the problem, because 1.1rc3 has added the random image function in register page, I must modify my current template to work with it, but what file i need to modify

[jerm]

register.template.php