Using a Disq. switch with the compenation of Dual LNBF (which needs 22Khz to be "on or "off) will cause the Blindscan not to work as it should.
you need to adjust the 22KHz (on/off) depending on which satellite you are watching . However I would recommend a single Sharp LNBF to avoid such conflict and you will notice that the speed of the blindscan will be much better and it will not miss any transponder. Cheers