invalid byte sequence for encoding "UNICODE"

Hi there.

Many times, I'm confronting with that strange problem: invalid byte
sequence for encoding "UNICODE". So, I guess, Postgresql can't allow me
to use some symbols which is not a part of UNICODE. But what is that
symbals?

I'm attaching a screenshot with THAT dead-symbol. As you can see - it's
an unknown symbol in the end of Cyrillic. First of all, I have checked
my data with iconv (iconv -f UTF-8 -t UTF-8 data.txt) and there are no
errors, so, I guess, there are no dead-symbols.

So the question is: is it possible to find a *table* with forbitten
characters for encoding "UNICODE"? If I can get it -> I can kill that
dead-characters in my program ;-)

Thank you.