Belive me...I tried all types of drivers and nothing seems to help,not even cord switch,but i found a solution to this problem,and its way too simple and easy.When someone says "All you have to do..." he knows nothing about it and he missed the thread.
I belive i have found a solution because after my Firmware Update of Jelly Bean 4.2.2 my Telefunken tablet couldn't connect MASS Storage to PC...so i tried to reinstall my firmware so I turned it off and pressed "-"and "Switch button" and it switched on over safe mode...after i connected my USB cord it prompted me to turn on the Mass Storage...after i did it showed up on my PC!!!
!!!!Just switch on using "Safe mode" it works!!! Happy New Year!
Did you use safe mode on your PC or safe mode on your phone? I hate safe mode on the phone because when you go back all your widgets have been deleted and you have to set them all up again. It would be a pain to do that every time you needed to connect your phone to your computer.