--- message-chunks.rb.orig	2010-05-28 22:24:30.000000000 -0400
+++ message-chunks.rb	2010-05-28 22:24:37.000000000 -0400
@@ -149,7 +149,7 @@
     end
 
     def write_to_disk
-      file = Tempfile.new(@filename || "sup-attachment")
+      file = Tempfile.new(@filename.gsub("/", "_") || "sup-attachment")
       file.print @raw_content
       file.close
       file.path