diff --git a/ruby/lib/jam_ruby/jam_track_importer.rb b/ruby/lib/jam_ruby/jam_track_importer.rb
index 9fcafab35..f929a8545 100644
--- a/ruby/lib/jam_ruby/jam_track_importer.rb
+++ b/ruby/lib/jam_ruby/jam_track_importer.rb
@@ -779,9 +779,11 @@ module JamRuby
 
       tracks.each do |track|
 
-        found = unique_instruments[[track.instrument_id, track.part]]
+        key = "#{track.instrument_id} | #{track.part}"
+        found = unique_instruments[key]
         if !found
           found = []
+          unique_instruments[key] = found
         end
 
         found << track
@@ -797,13 +799,19 @@ module JamRuby
             else
               track.part = "#{track.part} #{count + 1}"
             end
+            count += 1
           end
 
-          count += 1
         end
       end
+
+      # debug output
+      tracks.each do |track|
+        puts "TRACK #{track.instrument_id} #{track.part}"
+      end
     end
 
+
     def sort_tracks(tracks)
 
       sorted_tracks = tracks.sort do |a, b|