Although I have not had time to resolve this Canon driver issue, I have found a great alternative. The iPhone 5s with its 8MP camera and light-sensitive pixels, is a fantastic document camera. In some respects, it's way better than a scanner. Even if I had my Canon scanner working, I would use it only for photo scans or when document size proportions are critical or archival priority. Scanners are good for that but othrwise might soon be obsolete for most documents. Scanners are becoming archaic given their slowness. I love them for archiving very old photos as TIFFs mostly.
In the 7 days that I've had my new iPhone, I have photographed over a thousand index cards full of notes, receipts, business cards, news articles and other things. Using my iPhone is way faster than using any scanner. I import these snapshots into iPhoto daily and use the edit/rotate function if they need rotation.
The quality of iPhone document snapshots is absolutely astonishing. And I'm just holding the iPhone by hand, not even mounted to keep it perfectly still The iPhone autofocus is extremely sharp. With moderate diffused light, I can even shoot a huge article occupying most of a newspaper page after I have underlined everything of interest. It picks up even the finest print used in photo credits. The sharpness of the camera seems better than the human eye.
The file size on iPhone doc shots is a factor to consider but not excessive compared to my typical 150 line per inch document scanning. You can always do batch image size/resulution changes in a photo editor like Photoshop. Or you can shoot each doc from a greater distance and crop them in iPhoto to reduce file size. But I generally don't bother.
Naturally you may want to hold the iPhone close or far to photograph only what you want. You can easily improvise a copy stand by cutting a view hole in an upside down clear plastic box. Search "images copy stand for iphone" and you will find lots of iPhone copy stands you can purchase or improvise. I suspect that iPhone copy stands are going to become a hot trend especially if someone makes one that is adjustable height and pocket foldable. And I would imagine there will be an app for iPhone doc snapping with variable resolution, if such an app does not already exist. Doc snapping is about to come of age.
Another nice thing about using iPhone as a doc-cam is that you can keep your scanner off the desktop except for special projects like scanning photos. I love my iPhone 5s. Sorry Canon!