Hi Theo - Let's begin troubleshooting.

First, what subject IDs are you using for these sessions?

Is your data being saved to the default data location, or does your preference file specify an alternate location? To check if you're using an alternate data folder, open up MediaLab, select the 'Preferences' menu item, and navigate to 'Edit Preferences'. From here a window will open. Is the 'Use Alternate Data Folder' textbox filled in?

What version of the software are you currently running? To check, simply go to 'Help' and then 'About MediaLab' .