I’m struggling with the single user nature of this Android tablet.
My kids are complaining that they don’t want all of the interruptions and notifications from the apps that I have installed. Frankly I agree with them, a Facebook window just popped up when I was writing this.
It would be easier if the front unlock screen was a real login screen.
Edward Vielmetti's Wordpress weblog 
Are you using Jellybean (4.2)?
Fred, I’m using whatever came with the D2 Pad that my kids got, which is 4.0.4 (“Ice Cream Sandwich”).
The rest of the D2 Pad review is here:
http://vielmetti.typepad.com/vacuum/2012/12/the-d2-pad-a-short-review-of-an-android-tablet.html
Ed, what I suspect Fred was alluding to is that Jellybean, at least on Nexus devices, supports multiuser:
http://support.google.com/nexus/bin/answer.py?hl=en&p=settings_users&answer=2865483&rd=1
It may be possible to flash those D2 Pads. I would take a browse through The XDA-Developer fora to look for leads.