Cannot download backup from admin

I checked in the wp-content folder and there was a .htaccess file there with the following code:

Order Allow,Deny
Deny from all
<Files ~ "\.(gif|jpe?g|png|css|js|xml)$">
Allow from all
</Files>

I saved a copy of this file before deleting it from the wp-content folder only (* always make a copy of any file before you delete so you can restore if you get into trouble). After this, I regain the ability to download the backups from the dashboard.

Thanks for your answer. I checked, but I do NOT have such a file in my wp-content.

This is now fixed for me in version 2.6.2. Obviously connected to how the home path was calculated as my install has wp-config.php stored outside of web root.

Thanks to @mikelittle for the bug report and plugin author for correction.