Update disabled - After effect

Hello, I have the famous After Effects software. However, when I use it, after a few manipulations (like writing text, changing the settings of an effect), the screen turns black, and there is a red bar at the bottom of the preview screen that says: "refresh disabled: finish editing the text to continue."
Then my screen stays black for a few minutes and then it goes back to normal. What can I do to make it return to normal right away?

Configuration: Windows 7 / Firefox 11.0