I've got a D7 installation for some time now, with a content type that has a "private file" field.
It was working just fine up until now.
My files usually got uploaded like: http://....com/system/files/curso/file.txt And they get saved inside: .../files/private/Private - accessible only to group members/[nodeid]/file.txt
Now I've created a new node with an uploaded private file: demo.txt
When its downloaded it gets this path: http://....com/system/files/curso/demo_1.txt
But I get "Not Found" when I click it because it gets saved in other location (?): .../files/private/curso/demo_1.txt
Notes
The _0, _1 etc are automatically added to the files when they are saved into the node.
I've tried accessing the file from its real location (.../files/private/curso/demo_1.txt) with no luck.
The "files" folder is directely inside public_html because the original setting was that way (the site comes from a D4.7, D5 and then a D6 installation).
It worked just fine with other files up until now. I've not done anything special (like installing new modules), except creating a few new node types and rebuilding the permissions.
What could I do? (BTW, I've read this information, and sadly it didn't helped).
Update - Error Logs:
[Mon Mar 02 12:37:40 2015] [error] [client 181.28.74.188] client denied by server configuration: /home/sitio/public_html/files/private/curso/demo_1.txt (I've found more info about this here)