Index: /branches/release-36/php/lib/block.mtsubcategories.php
===================================================================
--- /branches/release-36/php/lib/block.mtsubcategories.php (revision 1231)
+++ /branches/release-36/php/lib/block.mtsubcategories.php (revision 2100)
@@ -22,5 +22,5 @@
         #
         # sort_method takes precedence
-        $sort_order = $args['sort_order'] or 'ascend';
+        $sort_order = isset($args['sort_order']) ? $args['sort_order'] : 'ascend';
         $sort_method = $args['sort_method'];
 
@@ -34,4 +34,6 @@
                 require_once("MTUtil.php");
                 $current_cat = cat_path_to_category($args['category'], $blog_id);
+                if ( is_array( $current_cat ) )
+                    $current_cat = $current_cat[0];
             }
             if ($current_cat == NULL) {
Index: /branches/release-36/t/35-tags.dat
===================================================================
--- /branches/release-36/t/35-tags.dat (revision 1652)
+++ /branches/release-36/t/35-tags.dat (revision 2100)
@@ -453,4 +453,6 @@
 { "r" : "1", "t" : "<mt:setvar name='foo' value='poge'><mt:if name='foo' eq='hoge'><mt:else>value is <mt:var name='foo'></mt:if>", "e" : "value is poge"}, #401
 { "r" : "1", "t" : "<mt:setvar name='foo' value='1'><mt:if name='bar'>true<mt:else>false</mt:if>", "e" : "false"}, #402
-{ "r" : "1", "t" : "<MTTags glue=',' sort_by='rank'><MTTagLabel> <MTTagRank></MTTags>", "e" : "verse 1,rain 2,anemones 4,grandpa 6,strolling 6"} #403
+{ "r" : "1", "t" : "<MTTags glue=',' sort_by='rank'><MTTagLabel> <MTTagRank></MTTags>", "e" : "verse 1,rain 2,anemones 4,grandpa 6,strolling 6"}, #403
+{ "r" : "1", "t" : "<MTSubCategories category='foo'><MTCategoryLabel></MTSubCategories>", "e" : "subfoo"}, #404
+{ "r" : "1", "t" : "<MTCategories sort_by='label' sort_order='ascend' show_empty='1'><MTCategoryLabel>'<MTSubCategories><MTCategoryLabel></MTSubCategories>'</MTCategories>", "e" : "bar''foo'subfoo'subfoo''"} #405
 ]