Well, I would consider yourself lucky.
Most of us don't want it going to the default folder in AC.
I guess the first thing I would try would be to run the backup and check the boxes next to the three errors phrases. If you get an error, do one at a time until you figure it out. Are you getting a confirmation message?
You shouldn't have to, but are you running AC backup directly from the server? Run it as an admin (something you shouldn't have to do either).
Next, I would actually browse to the BACKUP folder in the AC folder and see if it can back up to that folder. Try it by browsing and try it by UNC. \\Server\Amazing Charts\Backup
If you can't back up to that folder, then it is likely a sharing or permissions problem. The Backup folder is a child folder and should inherit the same permissions as the AC folder. But, you may want to try actually giving it permissions and be sure the computer's user that it is backing up from has permission to access it.
