Summary: We bought one of these a year ago and after 6000 scans it has stopped scanning on duplex. I suspect that this is a problem with the drivers and "some computers". I am still not sure why this is. It may be the drivers or windows 7 or windows updates. I took it to an engineer who said it was fine.......I saw it working but when I reconnected it to my own computer it froze when scanning duplex.
Summary: We have at least 70 to 80 of this model scanner in a large outpatient Medical group. They are excellent when they are working well, but when they fail they fail hard. For the amount that these scanners cost ( the price of this unit is outlandish ) they should work trouble free for 3 years minimum. They come with a 1 year manufacturers warranty which is most definitely not long enough. We have a pile of about 20 defective ones in a closet that are less than 3 years old.