Error "Object Already exists"

I am using Rational robot for Automation and sometimes i get errors stating " Object Aready exists" and "script \connection is locked up"(do not remember the exact error:o) at the time of execution (when i execute [copies of ] same script from 3-4 machines which acccess same database tables).
is this because i m accessing same table from 3-4 scripts at the same time??

I am sure that the error is not because of accessing the table by multiple scripts at the same time. It should be for some thing else