I just spoke to Dell tech support.  They are sending necessary materials to return the tablet.  They gave me no problems and seemed happy for me to send it back for testing and repair.

I'd suggest anyone still having problems to call them and get your tablet returned for repair/replacement.  It has to be hardware and not software...in my estimation.

Same issue! Apart from that the tab starts behaving erratically ,closing & opening , can't even shut . This happening after updated to 4.4.2 

Dell please issue a fix ASAP.Doesn't want to factory reset 

BTW, here's their tp no: 1-800-624-9897

Find the Express Service No of your tablet and enter that when asked to.  The no. is on the back of the tablet.

That seems like a stretch,  so many hardware failure after an upgrade??? 

I'm having screen going black after upgrading a venue 7 to 4.4.2.  Plus some other quirky touch touch screen problems.  This was a great tablet but not any more.   Very annoying! 

UPDATE: With 2-3 full power off & restarts the issue of black boxes seems to have reduced.... Erratic flickering too have reduced or almost gone....but sometimes touch behaves like it has been stuck , have to wait or restart corrects it. Seems the tablet stabilized a bit after the update to 4.4.2 after using it for few days....hope it improves further....