The reason is: More then one user is trying to update the same request number and due to some reasons the first request was not made commit because of abrupt browser window close. DBAs, killed the entire connection for that database user.
Sascha, Can you kindly explain about this Server.CONF line.... Whether this line overrides the above above inconsistency?
That's what it is meant to do. When set to true two users may change the same request at the same time and both changes are saved as long as they did not change the same field. This should also work for notes and references. So, I don't see an obvious reason to set it to false, but on our instance it was set to false initially.