Oops, default type and creator were reversed.
diff --git a/Mac/Python/gusiconfig.cpp b/Mac/Python/gusiconfig.cpp
index dc33134..db46619 100644
--- a/Mac/Python/gusiconfig.cpp
+++ b/Mac/Python/gusiconfig.cpp
@@ -119,7 +119,7 @@
    	if ( prefrh != -1) CloseResFile(prefrh);
 	UseResFile(oldrh);
 
-	config->ConfigureDefaultTypeCreator('ttxt', 'TEXT');
+	config->ConfigureDefaultTypeCreator('TEXT', 'ttxt');
 	config->ConfigureSuffices(
 		sizeof(sSuffices)/sizeof(GUSIConfiguration::FileSuffix)-1, sSuffices);
 	config->ConfigureAutoInitGraf(false);