> Have you checked if the trigger is still active, maybe it was disabled?

Yes I've checked it. The trigger is enabled and nobody disabled it before. I'm the only one who changes such things...

> In the face of bugs or a corrupted database, of course anything is possible, but that should -
> in most cases - still produce errors.

Well... of course, now that I'm testing it, the trigger fires as expected. The database is quite big, but as far as I can tell (I've searched trough the metadata) nothing is deleting records from the table "sto_cantidades"... that's why I asked if someone had a similar experience, on triggers "not being fired"

Of course, I'm still looking into my code... I don't discard the chance that in some hidden and oscure place I'm deleting by mistake those records!!! :)

> Not related to your problem, but using insert ...
> select is probably more efficient (and simpler to read in my opinion)

Yes! could be done that way. Thanks for the advice!!!

Sergio