diff -up system-config-printer-1.2.5/installdriver.py.uint32 system-config-printer-1.2.5/installdriver.py
--- system-config-printer-1.2.5/installdriver.py.uint32	2010-10-29 14:42:04.310843583 +0100
+++ system-config-printer-1.2.5/installdriver.py	2010-10-29 15:30:47.524996563 +0100
@@ -49,7 +49,8 @@ class PrinterDriversInstaller(dbus.servi
         interaction = "hide-finished"
         debugprint ("Calling InstallPrinterDrivers (%s, %s, %s)" %
                     (repr (xid), repr (resources), repr (interaction)))
-        proxy.InstallPrinterDrivers (xid, resources, interaction,
+        proxy.InstallPrinterDrivers (dbus.UInt32 (xid),
+                                     resources, interaction,
                                      reply_handler=reply_handler,
                                      error_handler=error_handler,
                                      timeout=3600)
diff -up system-config-printer-1.2.5/ppdsloader.py.uint32 system-config-printer-1.2.5/ppdsloader.py
--- system-config-printer-1.2.5/ppdsloader.py.uint32	2010-10-29 14:42:04.323844010 +0100
+++ system-config-printer-1.2.5/ppdsloader.py	2010-10-29 15:30:47.525996440 +0100
@@ -169,7 +169,8 @@ class PPDsLoader:
             interaction = "hide-finished"
             debugprint ("Calling InstallPrinterDrivers (%s, %s, %s)" %
                         (repr (xid), repr (resources), repr (interaction)))
-            proxy.InstallPrinterDrivers (xid, resources, interaction,
+            proxy.InstallPrinterDrivers (dbus.UInt32 (xid),
+                                         resources, interaction,
                                          reply_handler=self._packagekit_reply,
                                          error_handler=self._packagekit_error,
                                          timeout=3600)