>>>>Deleted record was the solution.
>>>>Late coworker had added a place to delete records I've never thought off.
>>>>
>>>>Customer seems to use this on regular base, but normaly the garbage collection catches the problem.
>>>>
>>>>(>ლ)
>>>
>>>An index on !deleted() may help
>>>

>>>index ..... for !deleted() 
>>>

>>
>>Changing tableupdate(0, to tableupdate(.T., solved it an instance without touching the index. It was very simple. :) I will keep the FOR clause of INDEX in mind, anyway.
>
>INDEX... for disables Rushmore optimization

Thank you.