Intergration error with Punbb and Wordpress - need help:)

Hi,

Seriously need some help here, as I have attacked all the solutions that I feel are available to me

Currently i’m trying to integrate punbb 1.2.6 and wordpress 2.3.3, i’m using Rickards excellent Jl-punbb user registration plugin that merges the user databases all that is working fine.

I have also allowed punbb to use wordpress functions via sharing the wp-blog-header in this line in a called file from my main.tpl

<?php
require('../wp-blog-header.php');
?>

And have integrated my main.tpl file with various offshoots importing various parts of my wordpress site too, for example the header is almost entirely imported.  And I’m using the wordpress login function in the header which works fine with the forum. 

However my problems arise with a call to an undefined wp function. This error only appears when I try to combine pages with the wordpress header and footer and the punbb forum sandwiched between. The full error is -

'Fatal error: Call to a member function hide_errors() on a non-object in /home/digitalp/public_html/wp-includes/functions.php on line 895'

and the only time it is triggered is when the forum/search.php is called from the forum, either by looking at the recently posts, or actually using the search function itself.  So while the error is wp related, it appears to be triggered by a punbb function, or is at least in some way related to a clash of variables or terms.

Here are the links that break the forum

<dl id="searchlinks" class="conl">
                <dt><strong>Search links</strong></dt>
                <dd><a href="search.php?action=show_24h">Show recent posts</a></dd>

                <dd><a href="search.php?action=show_unanswered">Show unanswered posts</a></dd>
                <dd><a href="search.php?action=show_subscriptions">Show your subscribed topics</a></dd>
                <dd><a href="search.php?action=show_user&amp;user_id=2">Show your posts</a></dd>
            </dl>

And this is the function in questions from wordpress wp_include/functions.php

function is_blog_installed() {
    global $wpdb, $db, $pun_config, $pun_user, $lang_common;
    $show = $wpdb->hide_errors();
    $installed = $wpdb->get_var("SELECT option_value FROM $wpdb->options WHERE option_name = 'siteurl'");
    $wpdb->show_errors($show);

    $install_status = !empty( $installed ) ? TRUE : FALSE;
    return $install_status;
}

I have tried various methods to get them to co operate including globaling variables in various files etc and with no real success.

If I have missed any important details please let me know and ill add them as soon as possible.  I’m really posting as a last resort before I try to scrap the user login registration and I feel I have exhausted my current level of knowledge and what i'm been able to read already on these forums and on the wp support forums!

Thanks!