Index: admin_templates/incs/form_blocks.tpl
===================================================================
--- admin_templates/incs/form_blocks.tpl	(revision 14925)
+++ admin_templates/incs/form_blocks.tpl	(working copy)
@@ -539,6 +539,7 @@
 			<table cellpadding="0" cellspacing="0">
 				<tr>
 					<td id="<inp2:{$prefix}_InputName field='$field'/>_path"<inp2:m_ifnot check="Field" name="$field" db="db"> style="display: none;"</inp2:m_ifnot>>
+
 						<inp2:$prefix_Field field='$field' db="db" result_to_var="category_id"/>
 						<inp2:m_include template="categories/category_path" category_id="$category_id"/>
 					</td>
@@ -552,7 +553,7 @@
 
 			         	<script type="text/javascript">
 							function processItemSelector($field, $selector) {
-								var $item_ids = $selector.Grids['c'].GetSelected();
+								var $item_ids = $selector.Grids[$selector.$Catalog.ActivePrefix].GetSelected();
 
 								CategorySelector.setCategory($field, $item_ids.length ? $item_ids.shift() : '');
 							}