thanks mvandam, 1 of the articles in your post solved the problem, with a slight modification to the original post..

i noticed the limits on my version, i think they're default now at 200 not 1000... but i had to reduce it even more to 150 and it solved the problem..

so the code i changed is as follows (quoted from BradM):

I made the following changes to /modules/system/admin/groups/groups.php:

Line 117:
if ($usercount < 200 && $membercount < 200) {

change to:
if ($usercount < 150 && $membercount < 150) {

Line 164:
$members =& $member_handler->getUsersByGroup($g_id, true, 200, $memstart);

change to:
$members =& $member_handler->getUsersByGroup($g_id, true, 150, $memstart);

Line 174:
$nav = new XoopsPageNav($membercount, 200, $memstart, "memstart", "fct=groups&op=modify&g_id=".$g_id);

change to:
$nav = new XoopsPageNav($membercount, 150, $memstart, "memstart", "fct=groups&op=modify&g_id=".$g_id);

I was also having trouble using the 'edit user' admin function. So I adjusted some values in /modules/system/admin/users/users.php:

Line 55 (or there abouts):
$nav = new XoopsPageNav($usercount, 200, $userstart, "userstart", "fct=users");

change to:
$nav = new XoopsPageNav($usercount, 150, $userstart, "userstart", "fct=users");

Line 55 (or there abouts):
$criteria->setLimit(200);

change to:
$criteria->setLimit(150);

solved all the current problems.. thanks again mvandam & my thanks to BradM for the original post that put me on the right track..