Toshiba has disabled Fastboot in Android images that support DRM content, as a security measure in compliance with Toshiba's security policy. 

For developers or users that require this function, Toshiba supports rolling back to a previous Android image with Fastboot. After the image has been rolled back the Fastboot function will be restored, however DRM-enabled content services such as Google Videos will not be available. 

Please note that image updates that support DRM content will continue to be offered to the user through the Service Station update utility.  User’s requiring Fastboot should not Install these updates, as doing so will, once again, disable this function.

Installation Procedure

Procedure to Roll Back the Android image and restore the Fastboot function.

http://download.toshiba.com/PreImageUpdateApp5.apk

1. Select the URL above to download the Image Update APK to the tablet.
2. Make sure your tablet is plugged into AC power.
3. Locate the APK file in your downloads and tap to install.
   1. It may be necessary to select the settings option to, install from unknown sources, before the APK install can be completed. 
4. Run the Service Station update utility (as directed in the User’s Guide).
5. Touch the Check for Updates button to access all available updates.
6. Select and download the update titled “Thrive™ 3.1.01.5.0032 System Image Update”.
7. Once the download has completed touch the Update System Icon to install the roll back image.