Cocoa + CopyItemAtPath: toPath: fails when copying a folder from a removable storage to local machine

Question

Hi Guys I am trying to copy a folder from removable storage device to the local machine and i am using the function from NSFileManager class "copyItemAtPath: toPath:". It fails and the error description i get is as follows:

Error Domain=NSPOSIXErrorDomain Code=1 UserInfo=0x12f49d90 "Operation could not be completed. Operation not permitted"

I am able to copy files from removable storage device to the local machine using this method and i am also able to copy files and folders from local machine to removable storage usng the same method.

It would be great if any of you guys can decipher the error and let me know the details of how to get around the error in this particular case.

Thanks