Drupal 6: Having issues with multiple paged tables in pages with multiple tabs (JQuery UI tabs)
The problem was being caused by how the pager logic handles existing URI encoded parameters: it simply copies them, pre-pending any new URI encoded parameters used by the pager logic. The result being a duplicate of my 'active tab' parameter "tabset", the previous one present in a copy of the prior URI parameters, and the one I introduced in the paging link.

My solution was to parse the request URI myself inside my form logic, with knowledge that the first encountered "tabset" value is the active one, not the second (older) version at the end of the URI.

$activeTab = 0;
  $requestUri = $base_root.request_uri();
  if ($requestUri == '') {
    _devReport( '$requestUri is empty!' );
  }
  else {
    $requestArray = explode( '/', rawurldecode($requestUri) );
    // if course, this parsing logic is specific to my WebApp URI setup:
    if (($requestArray[0] == 'http:') &amp;&amp;
        ($requestArray[3] == 'WebApp')) {
      // this should always be true, but just in case:
      if ($requestArray[4] != '') {
        $split1 = explode( '?', $requestArray[4] );
        $split2 = explode( '&amp;', $split1[1] );
        if ($split2[0] != '') {
          $split3 = explode( '=', $split2[0] );
          if ($split3[0] == 'tabset') {
            $activeTab = $split3[1];
          }
        }
      }
    } 
  }


Now $activeTab has the correct value, even though it may be present a 2nd time in the URI with a different value.