[mythtv-users] strange DVB-T problem with Terratec Cinergy Diversity

[Thor]

hi all,

this makes me go crazy. I've moved the machine from one room to another, 
same floor, appr. 10 meters. 
the cinergy is a dual-tuner usb device.
one antenna connected to both jacks on the stick, one input source for 
both tuners.
from 30 channels, there is a single one which is only "working" on the 
second tuner. if i try to tune it one the first one, i see 100% signal, 
but only get partitial lock (L__), thus never see a picture.
the logs don't help much.
where to go from here ?
is there an easy way to tell myth that this channel is only available on 
the second tuner, beside working with two input sources ?
i don't like to remember it for each recording to tell "prefer tuner 2".

thanks
thor