Images have wrong path when using private files and absolute Windows file directory

When I use private files download the thumb and the image when viewing a node gets the wrong url.

The thumb URL when uploading an image is expected to be:
http://www.example.com/?q=system/files/imagefield_thumbs/filename.png&12...
I'm getting this:
http://www.example.com/?q=system/files/C%253A/ABSOLUTE_PATH_TO_PRIVATE_F...

When viewing the node I'm expecting the image to get this URL
http://www.example.com/?q=system/files/filename.png&1286050779
I'm getting this:
http://www.example.com/?q=system/files/C%253A/ABSOLUTE_PATH_TO_PRIVATE_F...

Config:
Default settings for Image widget

OS Windows
Drupal 6.19
CCK 6.28
Imagefield 3.7
File permission OK
Private file download

Luckely I have 7 lines of code that fixes this.
In imagefield.module:

function theme_imagefield_image(...) {
...

Add these 4 lines

if (variable_get('file_downloads', FILE_DOWNLOADS_PUBLIC) == FILE_DOWNLOADS_PRIVATE) {
    $short_path = preg_replace('/^' . preg_quote(file_directory_path(), '/') . '/', '', $file['filepath']);
    $file['filepath'] = $short_path;
}

// Encode the parts of the path.
$parts = explode('/', $file['filepath']);
...

In imagefield_file.inc:

function imagefield_file_admin_thumb_path(...) {
...

Add these 3 lines

if (variable_get('file_downloads', FILE_DOWNLOADS_PUBLIC) == FILE_DOWNLOADS_PRIVATE) {
    $filepath = 'imagefield_thumbs' . $short_path;
}

return $filepath;
}

That should hopefully do the trick.