Firmware upgrade fixed battery life problem - hopefully

I, too, have been very disappointed with the battery life on my 3100. Finally, yesterday I emailed Nikon support about it and received a very nice reply within a couple of hours (on a Sunday, even). The technician had me check the firmware upgrade (I had v1.2) and said I needed v1.3. I downloaded and installed it with no problem, put in freshly charged batteries and proceeded to take 75 pictures over a period of 4 hours just to see how it would work. About half were flash, indoors and the rest outside. I'm not saying for sure this has solved the problem but for now it's working 1000% better than it did prior to the upgrade.