Hello Cliff,
We have the exact same Dell Venue model in our shop and we have experienced this problem. We solved this by using one of our SA124 y-cables and only using the data portion of the y. We will ship you a y-cable if you do not have one so you can use the device with your Dell tablet. Call me at 1-800-260-TEST Ext. 2 from 8-3 PST and I can set you up with a free cable.
Regards,
A.J.