I modified helperphp.php in the DW6 Configuration folder: Configuration\Shared\Webassist\DigitalFilePro\helpers\ on Windows 7
Now it's all fine. Must remember to change this when I update DataBridge.
Here's the extra code at line 81:
$baseFileName = preg_replace('/\.[^.]*$/', '', $uploadedFile["name"]);
$baseFileName = preg_replace('/[^A-Za-z0-9]/', '_', $baseFileName); // replaces all chrs & spaces except UC or LC letters & numbers with underscore
$baseFileName = preg_replace('/_+/', '_', $baseFileName); // Trims underscore: '___' >> '_'
$baseFileName = strtolower($baseFileName); //DGW makes lowercase
Cheers
Dave