Some unprotected pdfs with Membership Plugin and Download Manager Pro

Hi, I am using the Membership Plugin and Download Manager Pro.

Since Download Manager Pro doesn't have the ability to create a login or just password for a page; the password must be entered for each download or package of downloads, so I decide to use the Membership plugin for the content protected page "Investors" , which includes downloads.

In the Membership plugin options I the default uploads location is:
http://mywebsite.com/alpha/wp-content/uploads/
I have complete masking set.

The actual location of the files are located in:
http://mywebsite.com/wp-content/uploads/download-manager-files/

but the url in the browser is, i..e. http://mywebsite.com/alpha/downloads/

If I have I a PDF download in the content restricted area — i.e., a file download named"reports2012.pdf" — the restriced content page works fine - they can’t see or download the file until they are logged in.

But, if I’m logged out and I put "http://mywebsite.com/alpha/downloads/report2012/" in the browser url, I am brought to a page where I can download the pdf without password protection.

How can I protect this link - and links like it - as well?