Index: firmware/target/arm/usb-fw-pp502x.c
===================================================================
--- firmware/target/arm/usb-fw-pp502x.c	(revision 16260)
+++ firmware/target/arm/usb-fw-pp502x.c	(working copy)
@@ -134,6 +134,15 @@
         DEV_INIT2 |= INIT_USB;
 #endif
     }
+    /* if USB is detached, disable the USB-devices */
+    else
+    {
+        DEV_EN &= ~DEV_USB0;
+        DEV_EN &= ~DEV_USB1;
+#if CONFIG_CPU == PP5020
+        DEV_INIT2 &= ~INIT_USB;
+#endif
+    }
     
     return retval;
 }