How to solve ghost-volumes of an airport extreme connected hdd?

Question

Hi.
I use an airport extreme (latest firmware, airport utility 5.6, Lion 10.7.5) to connect to a usb drive (HFS+ format).
Also tried different authentification options (account, airport password) - all with the same problem.
I start the mac and see this in my terminal:
xy-Computer:Volumes "UserName"$ ls
Macintosh HD                                   HD       
HD-1                               MobileBackups
I have a duplicate Volumes now which I can access as follows:
HD is empty but in physically on the usb hdd.
HD-1 is pointing to the physical content on HD - which messes up my configuration of software who need access to /Volumes/HD/Shared/
This workaround fixes the ghost folder:
I disconnect aiport
I delete the folder HD
sudo rm -rf HD
(HD-1 , the ghost folder cannot be deleted by the way
HD-1/: resource busy
> Now I connect again and only the real folder and everything works again:
My-Computer:Volumes "My"$      ls    
Macintosh HD                 HD                 
MobileBackups                                  
What is this problem - how can I get rid of it?
It happens every day and deleting and stuff really is no fun. Is there a permanent solution?
I found an answer related to my topic on the internet but even as it explains something, it doesn't solve the prob.
http://superuser.com/questions/20879/how-to-remove-duplicate-ghost-network-drive -on-os-x
Mac OS X mounts drives by default by creating a folder with the name of the drive in /Volumes and then mounting it at that point (so a drive is normally accessible via /Volumes/NAME_OF_DRIVE). Mac OS X will append a -# after the name of a hard drive if multiple drives of that name are mounted. (eg. /Volumes/NAME_OF_DRIVE-1 and /Volumes/NAME_OF_DRIVE-2, etc.) This will also occur if a folder exists in /Volumes/ by that same name. Even though the mount point has a different name the name of the drive will show correctly in the Finder.
An example of what can cause an erroneous folder:
A script or application that writes a file to /Volumes/ExternalDrive/somefile.txt or even an application that when checking if a file exists (eg. open last saved document) creates a new document at that location when the hard drive/network share/USB key/etc. is not mounted. The file will exists at /Volumes/ExternalDrive/somefile.txt meaning the folder /Volumes/ExternalDrive will exist when you next mount.
Fixing this:
Ensure all drives have been unmounted - use Disk Utility or diskutil list to be sure
Check to see what can be seen in /Volumes/ - recommended to use the Terminal and use ls -laF /Volumes. There should only be one folder (NAME_OF_STARTUP_DRIVE -> /)
Delete the remaining folders. (I'd recommend checking the contents first)
Yes, there is an application I use which checks if a folder exists (not particulary a file). It connects to /Volumes/HD/Shared/ and tries to create the folders there if they don't exist. If it is started before the airport usb drive is accessed, ghost folders problem occures.
Any advice?

Answer 1

Update.
I use the airport drive now as supposed to.
But after going to sleep (drive or macbook - can't say for sure) opening the aiport drive appears to work, it connects and is readable. When I then try to write something, an error message appears:
some text -50
Can't write on the disc. Then I have to disconnect and connect agaiin or reboot.
Strange, isn't it? It seems like a drop out or permission problem of the airport extreme station. I use a network lan, no wifi.