Hi guys

I finally I have solve this problem... thanks to all of you.

Thanks to Martin, Martijn, Helen, John, Richard.

While all of us where paying attention so much to the triggers or SP
that could cause the problem. I later found out that there is a VIEW
that includes this "type" field. What I did is recompile the view and
try to edit the table with the "type" field. And at last everything
works fine.

Could this serve as a suggestion on improving the firebird? why is it
there is a need of recompiling the view?

Sorry for causing so much trouble to all of you! Thanks a lot a greatly
appreciates it.

James