I would call Sage's Software support, you proved it isn't your hardware as you can twain scan to MS Office. You need to know how they support the twain scanner within the program. I haven't dealt with Sage, but we have had other accounting & doc mgmt programs not interface correctly and it is usually a matter of setting up the scanner in the software program.
Just a note, once we show the scanner can scan to the workstation we explain to the customer that the problem is with thier software, not the equipment. Any additional labor for us to continue would be chargable, and that we will need to work with the software company to help them fix the problem.
Some software packages try to handle the TWAIN calls directly. I can't recall using a software package that does this ever working. Most of the time there is an option in the software setup to show the scanner's TWAIN controls - this has always worked for me.
It's kind of the same thing we run in to from time to time on the print side, when a program is written to simply forward PCL to the port of the selected printer, circumventing any driver settings (including prolog stuff).
