The digest notification is simply not working. At first I thought it was because something wasn't set up properly or notifications weren't enabled by the user or whatever but now I'm thinking different. Surely you knowledgeable folks can help with this?

On the NewBB admin index page this is displayed:
Digest notification
Should be sent out 19122715 minutes ago | Digest archive 0
(Should be sent out... is link /modules/newbb/admin/index.php?op=senddigest)

When clicking on the link with debug enabled the following appears:
Digest NOT processed

If the page does not automatically reload, please click here

[size=x-small]Notice [PHP]: Only variables should be assigned by reference in file modules/newbb/class/forum.php line 748 (There are 7 of the same notices so I'm only including one)

Warning [PHP]: array_keys(): The first argument should be an array in file modules/newbb/class/digest.php line 249
Warning [PHP]: implode(): Bad arguments. in file modules/newbb/class/digest.php line 249[/size]

After reading information on the dev site (see below) I tried to send the digest this way:
modules/newbb/digest.php
and received the following errors:
[size=x-small]Notice [PHP]: Only variables should be assigned by reference in file modules/newbb/class/forum.php line 748 (There are 7 of the same notices so I'm only including one)
Warning [PHP]: array_keys(): The first argument should be an array in file modules/newbb/class/digest.php line 249[/size]

When trying to run newbb/admin/admin_digest.php (Digest Manager on clicking Submit) the following appear:

[size=x-small]Warning [PHP]: implode(): Bad arguments. in file modules/newbb/class/digest.php line 249
Notice [PHP]: Undefined index: digest_id in file modules/newbb/admin/admin_digest.php line 52
Warning [PHP]: Invalid argument supplied for foreach() in file modules/newbb/admin/admin_digest.php line 54
[/size]
Here are the lines of code from the files. Does anyone see anything wrong with these?
newbb/class/digest.php line 249: $forum_criteria = ' AND t.forum_id IN (' . implode(',', array_keys($access_forums)) . ')';

newbb/admin/admin_digest.php lines 49-58:
xoops_cp_header();
switch($op){
case "delete":
$digest_ids = $_POST['digest_id'];
$digest_handler =& xoops_getmodulehandler('digest', 'newbb');
foreach($digest_ids as $did => $value){
$digest_handler->delete($did);
}
redirect_header( "admin_digest.php", 1);
break;


Using XOOPS 2.2.4, NewBB 2.0.2, (Preferences set to Digest enabled daily) PHP 4.4.2, MySQL 5.0.18-standard-log, Apache/1.3.33 (Unix).

Dev site about the digest:
Digest in NewBB 2.0
What is digest?

Digests are a special type of topics chosen/marked by moderators. These topics are usually highly valuable and can be viewed through 'view digest post' in the forum, as well as being sent to subscribers though PM or emails.

How is the digest handled in NewBB 2.0 ?

A. sending digest: if $xoopsModuleConfig['email_digest'] is set to 1 (daily) or 2 (weekly), the digest will be sent out by calling newbb/digest.php
Note: it is suggested to use cronjob for automatically sending out digest for the current version of newbb
B. prompt: the webmasters(moderators) are notified from the newbb/admin/index.php by being indicated the due time to send out the digest according to the set preference
C. managing sent digests: sent digests can be viewed or deleted from newbb/admin/admin_digest.php

Thanks.