This problem relates to the operation of the PC owner program. It handles the communications between users and all data collectors executing on an Lpar.
Two PC tasks can not use the same SSID (PCSSID parameter in the JCL). This information can be found in the CA Insight for DB2 for Z/os System Guide, Chapter 5: Operation and Customization, Operating the Program Call (PC) Owner, Troubleshooting. A careful review of this section is recommended to avoid this and other abends with this component.