Preferences tab, "Status msgs" button, then I think you have to create a new "status messages set" because I think you can't change the default if I remember correctly.
So, click on "new" for status messages set, give it a name (like "no popup set") and then disable the messages you don't want to see. I like to keep the "clock paused" pop-up, otherwise you can mistakenly leave the clock paused if you pause it for some reason.
I tend to pause the clock when I bust out players because my laptop is so slow that it takes probably 30 seconds to bust someone out with the delay between screens. If I forget to restart the clock, eventually someone sees the popup and tells me to restart the clock.