Data probe seems to have an issue automatically resizing itself to fit its contents.The issue seems to be the default behavior after installing Slicer. I think this has been going on for a few weeks now, I tested today with the nightly (Windows) and recorded a video:
This can be very annoying, but it goes away sometimes after resizing the whole window, or undocking/redocking the module panel from the main window.
By the way, I wanted to register an account on Mantis to report this, but it doesn’t allow me to create a new account. It says invalid security token any time I try to submit the new account registration form. I tried in two different browsers.