[Discuss-gnuradio] two stream in two cfiles

Hi all,  probably the last question of the year ;) I have a USRP v1 with 2 rfx900 daughterboard. Im trying to listen on two frequencies (one for each DB) and save the corresponding data in two differrent cfile. That at the same time.  Hence i tried to modify the uspr_rx_cfile.py using trick from multi_file.py But i dont really know how to configure the mux (seams it should be 0x32103210 but not sure). Moreover how do i deal with the number of channel when creating the source. And finally, how can i connect a stream from one subdevice to the first cfile output and the second stream from the other subdevice to the second cfile? Do i need a interleaver/deinterleaver? Thanks for your precious help. Best  wishes for 2010 to all of you,  regards,  sylvain