Hi Mythreya,
We are looking into this. Could you please help us and check something? Check that your screenplane still seems to be set up all right. You can do this from the settings panel. Firstly check that it identifies the screen correctly, and secondly that the two indented (barely visible) marks on the EyeX controller coinsides with the “scale-marks” drawn on the screen (i.e they should not be coincide with the full length of the Eye-tracker as with the REX). Errors with the screen plane can give errors of the kind you experience but it should not happen due to an upgrade, but it is nevertheless worthwhile to try while we are looking into other sources of error.
Please post here if this solves something for you.
/Mattias