I noticed that the device driver was gone. I repeated this a few times just to make sure I wasn't missing something. Does anybody know how to make sure the driver is not removed every time I re-boot?
The directory /dev is the working directory of subsystem 'udev' it is constantly reviewed, cleaned, corrected, modified or created each boot time, just like the /sys directory it is no longer a user specified content. There is no way you may place personal files therein: anything udev finds unreasonable (to it) shall be removed before proceeds to daemon mode.
Where scanner modules are placed depends upon the manufacturer's choice; some uses /opt/brand/scanner others use /usr/local/brand/sane. Here is an example how scanner
drivers are used and how it is configured.
If you have given enough information about your case other members may have been able to help you precisely. So after reading that link you should have enough idea what data the helpers here need to know to submit a better post.
Hope that helps.