posting with windows phone 8

I'm having a problem starting posts that I haven't seen on any other forum. When I activate the text box, the keyboard only bounces up for a split second before retracting again, so I can't input text. I've managed to start some through sheer persistence, and after rapid tapping, pressing, dragging, zooming, basically smearing my fingers all over the damn box, I still don't know what makes the keyboard finally stay open to use it.

Is there some account settings that would make this easier? Or is there a browser for wp8 that someone could recommend?