The R51.11 version of Q Home and Business does not recognize a shared network folder, if it is configured by Drive letter. Luckily, it will recognize the folder if you go through "network" and find the server and folder that way: as in "\\mynetworkserver\level1folder\myactualsharedfolder".
But if I have defined that on my system as a "drive" … for example T: , then I cannot save a backup to T:. I have to do it to the "\\mynetworkserver\level1folder\myactualsharedfolder"
This worked in the previous version, and I shall be sending a problem report.