Xe and Quantum Vertex on AS/400 Enterprise

Is anyone successfully running Vertex Quantum 2.4.2 Payroll and Sales/Use 2.1 on an AS/400 Enterprise Server with XP/2000 Clients? I am getting "failure to validate user handle" "failure to validate request handle". I have tried everything I know. If ANYONE has an answer for me HELP!!

There was a required IBM PTF on the JDE APAR list that fixed this problem for us. Best of luck...

Thank you so much for responding. Can you tell me how to get to this, I am not sure where to look for the JDE APAR List. Is that JDE.com, IBM.com?