Hi. I did the BIOS upgrade which didn't help but then I found the real problem - it was my mouse! The mouse works fine in all direction etc within Windows but outside of that it only works vertically. Using another mouse fixed the problem. Strange.  
Looking at the BIOS on my new 3910 I find the mouse pointer will not move vertically and gradually moves to the top of the screen. Keyboard arrows don't work properly either. I can't therefore view most the BIOS settings. In normal desktop mode my mouse works perfectly and otherwise the PC functions well. The BIOS is 1.0.3 and awaits an update; would this fix the problem?
Inspiron 3910 BIOS and mouse pointer don't work