Index: include/utils/UserInfoUtil.php
===================================================================
--- include/utils/UserInfoUtil.php	(revision 562)
+++ include/utils/UserInfoUtil.php	(working copy)
@@ -4550,6 +4550,12 @@
 	if($adb->num_rows($result) >0)
 	{
 		$permission = 'yes';
+	} else {
+		require 'modules/Calendar/CalendarCommon.php';
+		$ownerid = $adb->database->GetOne("SELECT smownerid FROM vtiger_crmentity WHERE crmid = ?", array($recordId));
+		if (in_array($current_user->id, getSharedDataUsers($ownerid, 'Calendar', 'read'))) {
+			$permission = 'yes';
+		}
 	}
 	return $permission;
 }