Make sure that the microphone is not blocked when recording a video or audio clip.
Tap the Menu key (touch key located at the bottom of the touchscreen) whenever you open an application to check the options that are available for that app.
If the device freezes up and stops working, press and hold the Power/Lock key (on the right side of the tablet) for about 6 seconds until the screen turns off. Wait a few seconds, then turn the tablet back on.