I played with the many options long enough and got it working. I do not know what the problem was. Along the process, it hung in other places as well. In my opinion, the system should never hang. It should timeout and give a relevant error message. Although having this support page is valuable and appreciated, it should be unnecessary in at least this situation. There is no bug in gscan2pdf that I am aware of; it just lacks error messages so that the user can debug the situation in most cases. Thanks...
gscan2pdf hangs on File Save
Handle tabs correctly
Need a quiet mode
That was it! Thanks! (Boy, is that embarrassing!)
That was it! Thanks! (Boy is that imbarrising!)
Here it is. Thanks!
sane_start: Invalid argument