I don’t understand the techie reasons, but you are always supposed to save files to/from the hard disk before going to an external drive (CD, USB, external hard drive). Initially I thought you just needed to do this when going between the PC and Mac. However, I’ve since learned that you should always do this to avoid problems.
So, if you’re getting an error message when trying to save or restore a file and you cannot seem to resolve the issue, try going to/from the hard drive first! If you cannot get a file to restore, you may need to have the file saved again–to the hard drive first.
Another quick note, when you’re trying to restore the data file, make sure to determine what file type you are restoring (QBW, QBB or QBM). It does make a difference which button you’ll choose when you restore.
Also, to send large data files to others you can use a file transfer service (many offer a free service) such as www.SendThisFile.com or www.YouSendit.com or others. Make sure the file requires a password and do NOT send the password in the message with the file–send it separately!