I helped a customer recently who was using Data Rescue 3 to recover data from the hard drive from his MacBook Pro that he is no longer able to use to startup his computer. He had replaced the drive and restored from a TimeMachine backup but most of his files from the past 6 months were not on the backup. He connected his old drive to his MacBook Pro using a hard drive dock and started scanning it using Data Rescue 3. During the scan he received a "Drive Failure Warning" because "Data Rescue has detected slow read access to one or more of your drives, which may be a sign of a failing drive". He did not know what to do at this point and contacted support for help.
I guided him to starting a clone using Data Rescue 3 to see if he could make a copy of this drive to a good drive that he could use to recover the data from. It took a few hours but he was able to successfully clone his 320GB and from there he ran the Deep Scan on the clone. He then recovered all of the data to another drive and was able to locate most of his files that were not backed up. He was very happy to get his files back using Data Rescue 3.