If you have a 106, 95x or 979 meter, it is possible the Autosave (File > Save Options) has been left unticked. This saves the averaged results over the length of time set in the Integration period. If the Autosave tickbox repeatedly becomes unticked, it is caused by one of two things: your memory is full, or the Autoname has run out of characters and is no longer able to assign an automatic number. In both cases, connect your meter to SvanPC++, download all your files and erase your memory. In the meter’s menu, select Autosave: Number, and edit the Autoname to e.g. @R1 to reset the naming sequence.