Error -47 usually means that your iDisk is already mounted in the Finder in Mac OS X. When this occurs, the Finder has gotten into a state where it does not recognize that the iDisk is mounted, but then finds that it cannot mount the iDisk because it is already mounted.This solution isn't very mac-like in the old point and click way of doing things.
You can check this by choosing "Computer" from the Go menu. If your iDisk does not appear there, do the following:
Restart the system
Launch Terminal from /Applications/Utilities/
In Terminal, type the following commands:
If you see an item in the window that matches your .Mac/iDisk username, type the following command:
sudo rm -r USERNAME
where USERNAME is the item that appears in the Terminal window. If you are prompted to enter a password, you will need to enter a Mac OS X Admin User password. You can verify that the item has been deleted by again typing:
Once this has been done, quit Terminal, then restart the system again. You should then be able to mount your iDisk properly.
I also ran Dragster too since I couldn't drag and drop my icons any more.