actually i wanted to say the tuner could be the problem.
remote on n900 is working well on a samsung lcd 2-3 years old, from about 2.5 - 3 metters, so i could say it is not the phone.
i'm looking at the tv-tuner receiver calbe ( 1-1.5 m), older technology, and probably a part of the signal is lost there.
my question is if someone is able to use remote programs on another pc tv-tuner.