Delphi and Paradox Problems

Problem 1
I have created a paradox database and it is being shared by multi-user.
I then create a form using form-expert using this database that I
have created. I store the executable file in a network drive.

When I run this executable file in two different machine and then
click on the DBNavigator's insert button at the same time. After
keying in all the records and then when I click on the post button,
only one record being saved to the database. And the other machine
will display a EDatabaseError. Could it be possible that both the
new records hold the same index number?

Problem 2
I actually created a form using an Interbase database. When I run
the executable file on a machine which does not have Delphi installed,
I got the following error message although I have already installed the
Local interbase deployment kit in the machine.
"exception EDBEngineError in module *.exe at 0003D0A0. Driver not
known to system. Alias: try."

Can anyone please help ?