“Error 404” on future posts (but not in firefox)

Ok, so far I have found out that future posts can only be seen by logged in users.

the weird thing is that i can see a category page (archive.php) with future posts (including content) on a browser i’m not logged in on.

but i can not see that future content as single.php. yet the code on these two templates is almost identical.this is an authentication issue, i think.i have searched for an answer, but to no avail.

any suggestions from anyone?

the whole piece of code looks like this:

// Check post status to determine if post should be displayed.
		if ( !empty($this->posts) && $this->is_single ) {
			$status = get_post_status($this->posts[0]);
			if ( ('publish' != $status) && ('static' != $status) ) {
				if ( ! (isset($user_ID) && ('' != intval($user_ID))) ) {
					// User must be logged in to view unpublished posts.
					$this->posts = array();
				} else {
					if ('draft' == $status) {
						// User must have edit permissions on the draft to preview.
						if (! current_user_can('edit_post', $this->posts[0]->ID)) {
							$this->posts = array();
						} else {
							$this->is_preview = true;
							$this->posts[0]->post_date = current_time('mysql');
						}
					} else {
						if (! current_user_can('read_post', $this->posts[0]->ID))
							$this->posts = array();
					}
				}
			} else {
				if (mysql2date('U', $this->posts[0]->post_date_gmt) > mysql2date('U', $now)) { //it's future dated
					$this->is_preview = true;
					if (!current_user_can('edit_post', $this->posts[0]->ID)) {
						$this->posts = array ( );
					}
				}
			}
		}

the first comment line says “Check post status to determine if post should be displayed.” so i think this is it but i am not a programmer. any help?