Sidebar login not working anymore with 2.7.1

Hello there,
I’ve an issue with my WP installation / custom theme.

I’ve a sidebar login since some months; now, with the upgrade at 2.7.1 it’s not working anymore; I’ve tried googling it and changed some code, but if I try to login it still points me out to the classic WP login page.

Here’s the entire code I’m using in the sidebar (calling it through an include: the login / user template is in a subfolder in my theme):

<div class="log">
<?php global $user_ID, $user_identity, $user_level ?>
<?php if ( $user_ID ) : ?>
<span class="userid">
		<?php global $user_email, $userdata;
			get_currentuserinfo();
			if(function_exists('get_avatar')) {
			echo '<span>' . get_avatar($user_email, '48').'</span>'; //display user's Avatar
		}
		?><i>Welcome back, <strong><?php echo $user_identity ?></strong></i>
<br />
<a class="buttonadmin" href="<?php bloginfo('wpurl') ?>/wp-admin/profile.php">Profile</a><?php if ( $user_level >= 1 ) : ?>
<a class="buttonadmin" href="<?php bloginfo('wpurl') ?>/wp-admin/">Dashboard</a><a class="buttonadmin" href="<?php bloginfo('wpurl') ?>/wp-admin/post-new.php">Write</a>
<?php endif // $user_level >= 1 ?>
<a href="<?php bloginfo('wpurl') ?>/wp-login.php?action=logout&redirect_to=<?php echo urlencode($_SERVER['REQUEST_URI']) ?>" class="buttonlogout"><strong>Log Out</strong></a>
</span>
<div class="clear"></div>
<?php elseif ( get_option('users_can_register') ) : ?>
<span class="userid">Howdy <strong>Guest</strong>, you may want to login...
<form action="<?php bloginfo('wpurl') ?>/wp-login.php" method="post" id="login-sidebar">
<input class="input" type="text" name="log" value="Username" onfocus="value=''" size="15" />
<input class="input"  type="password" name="pwd" size="15" value="Username" onfocus="value=''" />
<input type="submit" class="buttonlogin" value="login" />
<div class="clear"></div>
<a class="buttonregister" href="<?php bloginfo('wpurl') ?>/wp-register.php"><strong>Not a member yet? Join Now!</strong></a>
<a class="buttonrecoverpwd" href="<?php bloginfo('wpurl') ?>/wp-login.php?action=lostpassword">Forgot password?</a>
<span class="meta" style="visibility:hidden;float:left;margin-left:10px;margin-bottom:-15px;"><label for="rememberme"><input name="rememberme" id="rememberme" type="checkbox" checked="checked" value="forever" />Remember me</label>
</span>
<input type="hidden" name="redirect_to" value="<?php echo $_SERVER['REQUEST_URI']; ?>"/></span>
</form>
</span>
<?php endif // get_option('users_can_register') ?>
</div>

I’ve really no idea of what gone break… You can view it at adverbox.com (just launched some features for subscribers, and that’s not working anymore… I’m unlucky ??

Thanks in advance for your support!