Thanks for the respond. I hook up my A11 through USB2 box to my IBM notebook. But I have trouble with buffer underrun problem using software came with the A11(Ulead). Then I tried using the RecordNow(V7) which was pre-installed on my IBM notebook. The source is the default drive on the note book, target is the A11. I have no problem initially to disk copy 7 disks. The problem occured on the 8th disk. And from there on I have this error, be it setting source and target to A11, or copy from image file. However, strange thing is I'm able to backup data file uses DLA mode.