Unusual PK contraint error

Hi

I have a compostie primary key in my table comprising of 3 fields.
My systems tries to enter records in this table for which the combination of these 3 fields is not there at all

The new record gets inserted but with the following error being displayed on console

DBD::Pg::st execute failed: ERROR:  duplicate key violates unique constraint "pk_verify_mx"

I don't know whats goin on. Records get inserted but this duplicate key error is being thrown

~Jas