I have a 9900/9860 and my wife has a 9810. Difference between os7 and 7.1 there's option changes the browser more responsive those memory leaks are still there the battery increased on the later 7.1 builds. I recommend you go to 7.1 latest for 9810 I think is. 536 give it a go. If you need help bbos as a nice write up on how to upgrade os.
Hi I Have a BB Torch 9810 7.0 and I'm going Back & Forth on Weather I Should install 7.1, What Kinda Phone Do you Have? Who's your Carrier and What are the Differences Between 7.0 and 7.1