diff -urN tikiwiki-1.9.6/lib/tikilib.php tikiwiki-site/lib/tikilib.php
--- tikiwiki-1.9.6/lib/tikilib.php	2006-11-01 08:47:09 +1000
+++ tikiwiki-site/lib/tikilib.php	2007-07-12 10:37:11 +1000
@@ -1686,8 +1686,14 @@
 		    if (isset($res['groupname']) and $res['groupname']) {
 			$sections = split(",",$res['groupname']);
 			foreach ($sections as $sec) {
-			    if ($sec and !in_array($sec,$usergroups)) {
-				$display = false;
+			    if (substr($sec,0,1) == "!") {
+			    	if ($sec and in_array(substr($sec,1),$usergroups)) {
+				    $display = false;
+			    	}
+			    } else {
+			    	if ($sec and !in_array($sec,$usergroups)) {
+				    $display = false;
+			    	}
 			    }
 			}
 		    }
diff -urN tikiwiki-1.9.6/tiki-admin_modules.php tikiwiki-site/tiki-admin_modules.php
--- tikiwiki-1.9.6/tiki-admin_modules.php	2006-09-04 02:32:32 +1000
+++ tikiwiki-site/tiki-admin_modules.php	2007-07-12 10:37:11 +1000
@@ -278,6 +278,13 @@
 $smarty->assign_by_ref('orders', $orders);
 
 $groups = $userlib->list_all_groups();
+// Negation groups
+$neggroups = array();
+foreach ($groups as $grp) {
+	array_push($neggroups,"!$grp");
+}
+array_splice($groups, count($groups), 0, $neggroups);
+
 $allgroups = array();
 $temp_max = count($groups);
 for ($i = 0; $i < $temp_max; $i++) {
diff -urN tikiwiki-1.9.6/tiki-modules.php tikiwiki-site/tiki-modules.php
--- tikiwiki-1.9.6/tiki-modules.php	2005-12-15 05:37:34 +1000
+++ tikiwiki-site/tiki-modules.php	2007-07-12 10:37:11 +1000
@@ -68,33 +68,47 @@
 		} else {
 			$module_groups = array();
 		}
-		$pass = 'n';
+		$pass = true;
 		if ($modseparateanon !== 'y') {
 			foreach ($module_groups as $mod_group) {
-				if (in_array($mod_group, $user_groups)) {
-					$pass = 'y';
-					break; 
+				if (substr($mod_group,0,1) != "!") {
+					if (!in_array($mod_group, $user_groups)) {
+						$pass = false;
+						break; 
+					}
+				} else {
+					if (in_array(substr($mod_group,1), $user_groups)) {
+						$pass = false;
+						break; 
+					}
 				}
 			}
 		} else {
 			if(!$user) { 
 				if (in_array("Anonymous", $module_groups)) {
-					$pass = 'y';
+					$pass = true;
 				}
 			} else { 
 				foreach ($module_groups as $mod_group) {
 					if ($mod_group === "Anonymous") { 
 						continue; 
 					}
-					if (in_array($mod_group,$user_groups)) {
-						$pass = 'y';
-						break;
+					if (substr($mod_group,0,1) != "!") {
+						if (!in_array($mod_group, $user_groups)) {
+							$pass = false;
+							break; 
+						}
+					} else {
+						if (in_array(substr($mod_group,1), $user_groups)) {
+							$pass = false;
+							break; 
+						}
 					}
 				}
 			}
 		}
 	}
-	if ($pass == 'y') {
+	if ($pass) {
 // Commented out here too.  See zaufi's note in lib/wiki-plugins/wikiplugin_module.php	
 //		$cachefile = 'modules/cache/';
 //		if ($tikidomain) { $cachefile.= "$tikidomain/"; }