Gustavo,

> I tried starting a transaction with another Session
> component but, as I supposed, it didn´t worked because each
> transaction is independent of the other (the implicit one
> made by the BDE and the one I started in another Session).

I have completed several conversions from BDE to IB/FB and one thing I
learnt early on was to make the change from BDE to native components as soon
as possible, however if this isn't practical yet then you could write a
couple of wrapper functions like (not tested):

procedure TDataModule.StartTran();
begin
if (not DatabaseGeneral.InTransaction) then
DatabaseGeneral.StartTransaction();
end;

procedure TDataModule.Commit();
begin
if (DatabaseGeneral.InTransaction) then
DatabaseGeneral.Commit();
end;

procedure TDataModule.Rollback();
begin
if (DatabaseGeneral.InTransaction) then
DatabaseGeneral.Rollback();
end;

Now whenever you want to start a transaction simple call the wrapper
functions above instead of on the db its self. BUT I would *strongly*
recommend you change to IBO or even use TIB* components that come with
Delphi if you don't want to purchase any third party controls, as you will
see a significant improvement in speed/reliability.

Rgds

Si Carter
TECT Software Ltd
http://www.tectsoft.net/