quad lnb problem

hi people, got a problem with quad lnd and was looking a cure hopefully. got 3 cables going to lnb 2 for sky ± box and 1 cable for openbox ,when both boxs are on i can only watch vertical chs on openbox and when sky digi box is switched off i can then watch on channels on open box. i thought a quad lnb would work 100% for both boxs, what im i doing wrong,,,,roud:

hi i have a simular problem with my open box digi suggested it was an earth leak on the openbox shorting across the lnb but my problem was no high frequency channels V or H switching the sky sub box off cured it

edogg