On the customer's site we found a lot of protrace files that seemed to be generated after HANGUP signal. At least database log contains only the "HANGUP signal received" messages for the times matched the ones in the protrace files. These files are generated only if an end-user closes its terminal while Progress session was active. If an end-user does the same while, for example, at an application's menu then as expected a protrace file is not created. Progress 11.5.1 on Linux 64-bit. I failed to reproduce the issue using Progress 11.7 with the following code:

 for each customer no-lock: end.

Is it the feature of Progress V11.5 only? Or did I miss something?

P.S. The 'trap' command shows nothing for the customer's sessions.