Hi all,
I have been having a rough day with Apple Support, maybe you can help me.

I have an Airport Extreme (Firmware 7.4.1) with an external hard drive attached. Settings are so it is shared (but password protected) on the home network as well as over the internet (via bonjour).

I see two ways how I can connect and mount my disk:
1. Airport Disk: Only works when on the home network, in Finder I go to "shared", find the disk and connect to it. The Icon on the Desktop will look like a Drive that has the Airport bars on it.

2. Server: Works from Home Network and the Internet. In finder, I "go to server" and put in my IP address. When mounted, the Icon will look like a drive with three people holding hands on it.

My question: What is the difference?

I am using third party backup software (Crashplan.com) to back up to this drive. When using method 1, backups work fine, when using method 2, backups fail. Otherwise I have access to all the files on the drive using either method.