diff -rupN /data/home/redlizard/mnt/mediawiki-extensions-SemanticMaps-2.0.1/includes/forminputs/SM_FormInput.php ./includes/forminputs/SM_FormInput.php
--- /data/home/redlizard/mnt/mediawiki-extensions-SemanticMaps-2.0.1/includes/forminputs/SM_FormInput.php	2013-03-17 22:11:51.000000000 +0100
+++ ./includes/forminputs/SM_FormInput.php	2013-04-29 00:26:07.000000000 +0200
@@ -106,7 +106,7 @@ class SMFormInput {
 			}
 		}
 
-		if ( !is_null( $coordinates ) ) {
+		if ( !is_null( $coordinates ) && $coordinates != "" ) {
 			$parameters['locations'] = $coordinates;
 		}