OK, I've changed Connection Charset to WIN1252 and now transliterate
error has gone away.
But still persists another problem. There is a difference between
setting TIB_Query SQL property or TIB_Query Filter property.
If I set TIB_Query SQL property to
... WHERE descr like '%inclusão%'
it works properly and I get records I want from DataSet.
But, if I set TIB_Query Filter property to
descr like '%inclusão%'
it returns nothing from DataSet (FilterOptions=[fopCaseInsensitive]).
What's wrong?

--- In IBObjects@yahoogroups.com, Artur Anjos <listas@...> wrote:
>
> Check your connection settings.
>
> Artur
>
>>I've submited this clause directly to FireBird 1.5 Server and it
works fine:

>> SELECT * FROM Doc WHERE descr like '%inclusão%'

>> If I submit the same clause through a TIB_Query, setting it to
query's SQL property, I get a transliterate error.