"Possible Failure Running Task"?



When I erase unused disk space using the 1 pass method Task Properties > Statistics shows the task was run successful. When I use the 3 pass or 7 pass methods (the DoD methods) I get "possible failure" in Statistics, and when I look in the log file the only thing is says is "possible failure running task". What does this mean, specifically? Is there anything I can try to do to use the DoD methods successfully on unused disk space?
More Information

More information: I am using Windows XP Home Edition, NTFS file system. The hard drive is SATA connected to a VIA SATA Raid controller. Windows recognizes the hard drive (properly) as a SCSI Disk Device.
Possible Failures

I seem to be having much the same porblem that you are. I posted a request for help in this Forum on March 11, but got no replies. If anyone knows the answer (and I assume they do), they're not saying. Were you ever able to find out anything, and if so, can you give me any leads? I've tried everything I can think of and just can't get any results but "Possible Failures", and when I check out the unused HDD space, not much seems to have been erased.