Using flex4.1, Flash Builder giving error "flash.filesystem::StorageVolume could not be found."

Hi there,

          I'm trying to copy some files to Storage Card on a AIR application. Is this possible with the latest version of the AIR SDK (2.0)?

          I am developing in Flash Builder. I have downloaded the lastest flex sdk(4.1)  and used it.

          Flash Builder then recognises the StorageVolume and StorageVolumeInfo classes. However when I then run the app the debugger throws an error on the following line:

LINE:

var volumes:Vector.<StorageVolume> = StorageVolumeInfo.storageVolumeInfo.getStorageVolumes();

Note: I have imported both classes as well.