Description of problem:

In RHEL 5.7, the Wacom DTU-2231 display appears to not load the wacom driver.

output of udevinfo:

# udevinfo -a -p /sys/devices/pci0000:00/0000:00:1d.0/usb6/6-2/6-2.1

Udevinfo starts with the device specified by the devpath and then
walks up the chain of parent devices. It prints for every device
found, all possible attributes in the udev rules key format.
A rule to match, can be composed by the attributes of the device
and the attributes from one single parent device.

  looking at device '/devices/pci0000:00/0000:00:1d.0/usb6/6-2/6-2.1':
    KERNEL=="6-2.1"
    SUBSYSTEM=="usb"
    SYSFS{configuration}==""
    SYSFS{product}=="DTU-2231"
    SYSFS{manufacturer}=="Wacom Co.,Ltd."
    SYSFS{maxchild}=="0"
    SYSFS{version}==" 1.10"
    SYSFS{devnum}=="3"
    SYSFS{speed}=="12"
    SYSFS{bMaxPacketSize0}=="64"
    SYSFS{bNumConfigurations}=="1"
    SYSFS{bDeviceProtocol}=="00"
    SYSFS{bDeviceSubClass}=="00"
    SYSFS{bDeviceClass}=="00"
    SYSFS{bcdDevice}=="0103"
    SYSFS{idProduct}=="00ce"
    SYSFS{idVendor}=="056a"
    SYSFS{bMaxPower}=="  0mA"
    SYSFS{bmAttributes}=="e0"
    SYSFS{bConfigurationValue}=="1"
    SYSFS{bNumInterfaces}==" 2"

  looking at parent device '/devices/pci0000:00/0000:00:1d.0/usb6/6-2':
    ID=="6-2"
    BUS=="usb"
    DRIVER=="usb"
    SYSFS{configuration}==""
    SYSFS{product}=="DTU-2231 Hub"
    SYSFS{manufacturer}=="Wacom Co.,Ltd."
    SYSFS{maxchild}=="3"
    SYSFS{version}==" 2.00"
    SYSFS{devnum}=="2"
    SYSFS{speed}=="12"
    SYSFS{bMaxPacketSize0}=="64"
    SYSFS{bNumConfigurations}=="1"
    SYSFS{bDeviceProtocol}=="00"
    SYSFS{bDeviceSubClass}=="00"
    SYSFS{bDeviceClass}=="09"
    SYSFS{bcdDevice}=="0805"
    SYSFS{idProduct}=="00cf"
    SYSFS{idVendor}=="0531"
    SYSFS{bMaxPower}=="100mA"
    SYSFS{bmAttributes}=="e0"
    SYSFS{bConfigurationValue}=="1"
    SYSFS{bNumInterfaces}==" 1"

  looking at parent device '/devices/pci0000:00/0000:00:1d.0/usb6':
    ID=="usb6"
    BUS=="usb"
    DRIVER=="usb"
    SYSFS{configuration}==""
    SYSFS{serial}=="0000:00:1d.0"
    SYSFS{product}=="UHCI Host Controller"
    SYSFS{manufacturer}=="Linux 2.6.18-274.el5 uhci_hcd"
    SYSFS{maxchild}=="2"
    SYSFS{version}==" 1.10"
    SYSFS{devnum}=="1"
    SYSFS{speed}=="12"
    SYSFS{bMaxPacketSize0}=="64"
    SYSFS{bNumConfigurations}=="1"
    SYSFS{bDeviceProtocol}=="00"
    SYSFS{bDeviceSubClass}=="00"
    SYSFS{bDeviceClass}=="09"
    SYSFS{bcdDevice}=="0206"
    SYSFS{idProduct}=="0000"
    SYSFS{idVendor}=="0000"
    SYSFS{bMaxPower}=="  0mA"
    SYSFS{bmAttributes}=="e0"
    SYSFS{bConfigurationValue}=="1"
    SYSFS{bNumInterfaces}==" 1"

  looking at parent device '/devices/pci0000:00/0000:00:1d.0':
    ID=="0000:00:1d.0"
    BUS=="pci"
    DRIVER=="uhci_hcd"
    SYSFS{broken_parity_status}=="0"
    SYSFS{enable}=="1"
    SYSFS{modalias}=="pci:v00008086d00003A34sv0000103Csd0000130Bbc0Csc03i00"
    SYSFS{local_cpus}=="00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000"
    SYSFS{irq}=="169"
    SYSFS{class}=="0x0c0300"
    SYSFS{subsystem_device}=="0x130b"
    SYSFS{subsystem_vendor}=="0x103c"
    SYSFS{device}=="0x3a34"
    SYSFS{vendor}=="0x8086"

  looking at parent device '/devices/pci0000:00':
    ID=="pci0000:00"
    BUS==""
    DRIVER==""