Problem

When an InstantTranslate user has also the role editor, he is allowed to edit file translations.
When task is opened for editing all language resources that were used for pretranslation are assigned to a task probably with write access if they have write access as default asigned for the client (need to check this), but task tm is not created during that operation for some reason.
When a segment is changed by this user, it will immediately be saved to all TMs assigned with write access and this could be master TM because of absence of the task TM.

Solution

For InstantTranslate-tasks that are editable for users with direct access from InstantTranslate no TMs should be assigned with write access, even if they are configured with write access by default. Only exception: The specific InstantTranslate-TM for the language combiantion and client.

If a task is converted via "send to human revision" all TMs that are configured with "write access by default" should be assigned with write access. 

Also please ensure: After "human revision" workflow is ended and the file in InstantTranslate is available for download the user must NOT be able to edit it himself anymore via editor (because it has passed professional post-editing and the result needs to be preservered).