Tvheadend

Hi all
i live in IRAN and in this country some frequencies like BBC or VOA have parasite by government in some time ranges!
i have a problem with that. after installing tvheadend when i select this channels (if parasite is ON) this channels shown pixelized or green screen with pixilized (in weak parasite mode ,if parasite source have a grate power the channels not shown ). any way ...
after that if i switch to a non parasite channel ike a Music channels tvheadend show that same , like parasite chanel and i see pixlized and green screen and all channels too.
i used in putty Sudo service tvhedend restart but it does not solve this. but if i restart my pc its shown good until i open that parasite channels again!
is that problem for codec or something else ?
please help me for solve this problem.
tanks a lot.

for more information and see what happens to me :
*this attachment include 2 sample of channels AAA family and AAA music On yahsat (Y1A) that i first open BBC channel (parasite on it) and then i open AAA channels(non parasite channels ( that shown pixlized and bad ) ) *