ambigous error message

I tried to clone one drive to another, but the operation failed with the following error message: "Failed to move the selected data. Make sure that your new drive is not smaller than your old one and your partitions do not contain errors. You can check for the errors and correct them using a special utility." It would be great if Acronis eliminated this ambiguity by generating separate error messages for these two possible error conditions. I ran scans of both drives, and no errors were detected. The source drive is larger than the target drive, but this is not supposed to be a problem as long as the used space on the source drive is less than the size of the target drive. Have other people encountered this problem?