Casting omesso.

diff --git a/phcstats.py b/phcstats.py
index 33904e7..3c198d3 100755
--- a/phcstats.py
+++ b/phcstats.py
@@ -54,7 +54,7 @@ def DumpClientData(client, data):
                         data.items()))
     f = open(database_directory + client, 'w')
     for stat in data.items():
-        f.write (":".join(stat))
+        f.write (":".join(map(str, stat))
     f.close()

 def UpdateClientsData(client, alive):