Moving this discussion to the Adobe Digital Editions forum.
Their website doesn't say much about the "eBook reader", and the Adobe website doesn't list it as a supported device/application (http://blogs.adobe.com/digitalpublishing/supported-devices)
So it is quite possible that the eBook reader wont work with the Adobe system. However since it appears to be a fairly stock Android device (without the Google market placeI would suggest getting a copy of Bluefire Reader for Android instead, as it's know to play well with Adobe.
Thank you very much Jim! I appreciate your advice. I got Bluefire like you suggested. I first put it on my Android cell phone and I was able to authorize my cell phone for DRM. I then did a "factory" reset on my new tablet/ereader to make sure I erased any errors that I may have created. I put Bluefire on my tablet, and tried to authorize it, but again it "failed". I tried 3 more times. I then boxed up the tablet and returned it to Walmart. I think I will do more research and find a different tablet which is too bad because I really liked all the other features of the DOPO T708.
Pandigital makes some low end Android devices that may be worth looking at. Alternatively you can get a pre-owned Nook Color from B&N for $129. (Disclosure: I work for B&N - so I'm definitely biased here).