I guess REB1200 uses other servers to connect for bookshelves so if I'm not wrong you should add to privoxy settings the line "forward .softbook.net 127.0.0.1:9090".
Are you following me on why we are using privoxy, adding those lines, etc?
So, basically you need to do this:
1- Run Linreb (usually uses port 9090)
2- Run privoxy (usually uses port 8118)
3- add the lines "forward .ebooksystem.net LINREB_IP:LINREB_PORT" and "forward .softbook.net LINREB_IP:LINREB_PORT"
(where LINREB_IP is the IP address where Linreb is runnning and LINREBPORT is the port in which it listens)
4- Set the reader to use HTTP proxy pointing to the IP address and port of privoxy.
In the case that privoxy, Linreb and the reader are connected to the same PC just use 127.0.0.1 (I don't know why it didn't work when I use my PC's local IP 192.168.#.1)