I dont have a fix at this time, but i have logged the issue in our bug base to be corrected in a future update.
to prevent spaces in uploaded file names in the future, you can add the following at line 1 of pages that use the upload behavior:
<?php
if(sizeof($_FILES) > 0) {
foreach($_FILES as $k => $v) {
$_FILES[$k] = str_replace(" ", "", $v);
}
}
?>