diff --git a/calendar/inc/class.socalendar.inc.php b/calendar/inc/class.socalendar.inc.php
index dc7b2ff977..0d17e0034c 100755
--- a/calendar/inc/class.socalendar.inc.php
+++ b/calendar/inc/class.socalendar.inc.php
@@ -72,7 +72,21 @@
 		{
 			$extra = '';
 			$extra .= (strpos($this->filter,'private')?'AND phpgw_cal.is_public=0 ':'');
-			$extra .= ($this->cat_id?"AND phpgw_cal.category like '%".$this->cat_id."%' ":'');
+			//$extra .= ($this->cat_id?"AND phpgw_cal.category like '%".$this->cat_id."%' ":'');
+			if ($this->cat_id)
+			{
+				if (!is_object($GLOBALS['phpgw']->categories))
+				{
+					$GLOBALS['phpgw']->categories = CreateObject('phpgwapi.categories');
+				}
+				$cats = $GLOBALS['phpgw']->categories->return_all_children($this->cat_id);
+				$extra .= "AND (phpgw_cal.category".(count($cats) > 1 ? ' IN ('.implode(',',$cats).')' : '='.(int)$this->cat_id);
+				foreach($cats as $cat)
+				{
+					$extra .= " OR phpgw_cal.category LIKE '$cat,%' OR phpgw_cal.category LIKE '%,$cat,%' OR phpgw_cal.category LIKE '%,$cat'";
+				}
+				$extra .= ') ';
+			}
 			if($owner_id)
 			{
 				return $this->cal->list_events($startYear,$startMonth,$startDay,$endYear,$endMonth,$endDay,$extra,$GLOBALS['phpgw']->datetime->tz_offset,$owner_id);
diff --git a/infolog/inc/class.soinfolog.inc.php b/infolog/inc/class.soinfolog.inc.php
index dddd95123a..6f94c07579 100644
--- a/infolog/inc/class.soinfolog.inc.php
+++ b/infolog/inc/class.soinfolog.inc.php
@@ -518,9 +518,15 @@
 			}
 			//echo "<p>filtermethod='$filtermethod'</p>";
 
-			if (intval($query['cat_id']))
+			if ((int)$query['cat_id'])
 			{
-			  $filtermethod .= ' AND info_cat='.intval($query['cat_id']).' ';
+				//$filtermethod .= ' AND info_cat='.intval($query['cat_id']).' ';
+				if (!is_object($GLOBALS['phpgw']->categories))
+				{
+					$GLOBALS['phpgw']->categories = CreateObject('phpgwapi.categories');
+				}
+				$cats = $GLOBALS['phpgw']->categories->return_all_children((int)$query['cat_id']);
+				$filtermethod .= ' AND info_cat'.(count($cats)>1? ' IN ('.implode(',',$cats).') ' : '='.(int)$query['cat_id']);
 			}
 			$join = '';
 			if ($query['query']) $query['search'] = $query['query'];	// allow both names
diff --git a/phpgwapi/inc/class.contacts_sql.inc.php b/phpgwapi/inc/class.contacts_sql.inc.php
index 868891dca8..2b9b804d70 100644
--- a/phpgwapi/inc/class.contacts_sql.inc.php
+++ b/phpgwapi/inc/class.contacts_sql.inc.php
@@ -348,7 +348,21 @@
 					{
 						if($name == 'cat_id')
 						{
-							$filterlist[] = "(" . $name . " LIKE '%," . (int)$value . ",%' OR " . $name."='".(int)$value."')";
+							if (!(int)$value) continue;	// nothing to filter
+
+							//$filterlist[] = "(" . $name . " LIKE '%," . (int)$value . ",%' OR " . $name."='".(int)$value."')";
+							if (!is_object($GLOBALS['phpgw']->categories))
+							{
+								$GLOBALS['phpgw']->categories = CreateObject('phpgwapi.categories');
+							}
+							$cats = $GLOBALS['phpgw']->categories->return_all_children((int)$value);
+							$cat_filter = '(cat_id IN ('.implode(',',$cats).')';
+							foreach($cats as $cat)
+							{
+								$cat_filter .= " OR cat_id LIKE '%,$cat,%'";
+							}
+							$cat_filter .= ')';
+							$filterlist[] = $cat_filter;
 						}
 						elseif(@is_int($value))
 						{