If the AriaMX is placed on an unstable table, the instrument can't obtain a good reading of the plate.
The AriaMX uses cameras to detect fluorescence released if a copy of DNA is created in the qPCR reaction. The cameras move over each well of the plate to read this fluorescence after every cycle of qPCR. If the AriaMX is placed on an unstable table then the cameras can't obtain a good reading of the plate and this results in poor data as seen below.
Figure I: Screenshot of data from an AriaMX that was on a table that was not sturdy. If you see data like this change the location of your AriaMX to a stronger table or even to the floor.
What does Agilent say regarding location of the AriaMX?
From the Agilent Aria User Manual: