There is already an issue:
9549 that I just starred. All 7-8 threads in the instance died like that but noone seemed to reveal an issue. Is this the crude way applications are migrated from one server to another?
By the way don't look for this, in the Error Logs, you will not find it there, since this is just an informational message :-) I am sure the user on the other end of the POST will not agree...
Set your Filter: to status:5.* to get these in the logs Options box....