I've run into this with a couple clients. (oddly enough also for quickbooks hosting) I found the easiest way to get around it was to create a .cmd file and drop it in the startup folder. Contents would be:
net use x: /delete
net use x: \\computer name\sharename
The first line removes the map if it already exists, the second creates the map.
If the share requires a username and password, the second line would be:
net use x: \\computer name\sharename /user usernamehere userpasswordhere