[Nut-upsuser] Can't claim USB device

[Brandon Metcalf]

Just built and installed nut 2.4.1 with a usb.conf that looks like

  [trippb]
    driver = usbhid-ups
    port = auto
    desc = "Tripp Lite SmartPro 2200RMXL2U"

The OS is Ubuntu 8.04.2 with kernel version 2.6.24.

When trying to start the driver I get

  $ sudo ./upsdrvctl start
  Network UPS Tools - UPS driver controller 2.4.1
  Network UPS Tools - Generic HID driver 0.34 (2.4.1)
  USB communication driver 0.31
  Can't claim USB device [09ae:3012]: could not detach kernel driver from interface 0: Operation not permitted
  Driver failed to start (exit status=1)

The UPS is detected when connected.  From the output of dmesg

  [689484.575866] hiddev96hidraw2: USB HID v1.10 Device [Tripp Lite  TRIPP LITE SMART2200RMXL2U ] on usb-0000:00:03.0-2

lsusb also lists the UPS.

Any ideas?

Brandon