Error msg on startup: "...preferences.xml not a valid XML file, or you don't have permissions on it."

System Details:

Inkscape Version: 0.46
OS: Win XP, SP3
Hardware: Intel Core 2 Quad, 2.4 GHz // 3 Gigs memory // NVidia GeForce 8500 GT // "Genius" brand pressure-sensitive tablet, model M609

Problem Description:

When starting Inkscape, I get an error message that states:

"C:\Documents and Settings\(profile)\Application Data\Inkscape\preferences.xml not a valid XML file, or you don't have permissions on it. Inkscape will run with default settings. New settings will not be saved."

Background:

This problem started happening after I went into File --> Input Devices, and enabled "Pressure". There is a "Device" combo box at the top of that dialog; and the only item in the list was a string of garbled text, followed by "" Pressure Stylus"

Using the mouse to select the drop-downs would only give me an option of "none", "1" or "2"; but if I re-selected the garbled-text Input Device using the stylus itself, it then allowed me to set "Pressure" to "3". I can save the settings, and Inkscape works... but only as long as the program is running.

When I close Inkscape and run it again, it loads preferences.xml, and trips over the string of junk text:

°òÙà†ôxø" Pressure Stylus

After I got the error message, I looked at the preferences.xml file, and I found the same string of garbled text:

  <group
     id="devices">
    <group
       id="Core Pointer"
       mode="screen"
       axes="x;y;"
       keys="" />
    <group
       id="°òÙà†ôxø&quot; Pressure Stylus"
       mode="screen"
       axes="x;y;pressure;"
       keys="" />
  </group>

(I'm not sure if the garbled characters will display properly... if it helps, here are the unicode codes for each of the characters in that sequence before the ampersand: 00B0, 00F2, 00D9, 0003, 00E0, 2020, 00F4, 0003, 0078, 00F8.)

Does Inkscape just not recognize this tablet correctly? I have installed the latest drivers (driver version 3.33, firmware version 1.7, according to the "Pen Pad" tool in the Control Panel.

Other notes:

 - After I get the error message, the "Input Devices" dialog box now just says "Pressure Stylus" in the Device combo box (without the garbled text). Pressure sensitivity is disabled, and cannot be re-enabled (which makes sense, if settings cannot be saved).
 - I can fix the problem by simply editing the preferences.xml file, and deleting the garbage text so that it looks like id="Pressure Stylus" However, going back into that Input Devices preferences screen and saving preferences will cause the problem to return.
 - After manually fixing the problem, pressure-sensitivity actually *works* - however, if you go back into the Input Devices dialog box, it *looks* as if it was set back to the default settings (with "Pressure" set to "none" again).
 - This same tablet works fine with other programs (such as Photoshop), so I think that the problem is limited to Inkscape (though it might have something to do with the way that the tablet represents itself to the system, I'm not sure.)