USRP Request

I started a new project involving GNURadio and USRP.
I’m using
Ubuntu 11.10 and GNU Radio Companion v3.5.1-9-g4beff39a. The hardwares
I’ve got are: 2 units of USRP1 Rev 4.1 and DBSRX Rev2.1.
I’ve got 2 questions:

  1. These versions of USRP and daughter boards are still compatible with
    the version of the software above?
  2. Could you please show me how to set the USRP-Source in the
    Gnuradio-companion so that to target each daughter boards.
    For your information, the 2 USRP’s were long ago synchronized as master
    and slave. So I’ve got 4 units of DBSRX daughters boards.
    You help will be positively appreciated.