org.postgresql.util.PSQLException: FATAL: sorry, too many clients already

we have a project developed in soapUI 5.1.2 and we migrated to Ready API 1.2.2 using groovy 2.1.7 & postgresql-9.0-802.jdbc3. When i execute the project after 1 hour or so in the logs we see "org.postgresql.util.PSQLException: FATAL: sorry, too many clients already" and the testcases are failing to extract the data from the db due to this error. Apart from it we had also cross checked in the db "select * from pg_stat_activity" i dont see any of my connections are opened. whe had written a script in such away that we create connection , execute db script( select, cretae,delete) and we close the connection. we are facing this issue when we migrated to Ready API 1.2.2. Our scripts are working fine soapUI 5.1.2 pro. Any help is appreciated