Does it have 2 gb of memory before or after you update it? Also, Safari on an older device can use up to a gb of ram on an older iphone (according to what I have looked into.) So you might try freeing up at least 1 gb more of memory to see if that makes a difference. If you want to try to free up one gb more, I have a few places to look to see if that helps. On the ipad/iphone, both store pictures in a number of places both in photos app and the camera app. Photos on them also include the photo stream, the camera roll, and temporarily, the idevice will store a recently deleted photo for at least 23 days (on mine right now) before completely deleting it. So you might start there to free up some space. Many games are linked to the Game Center, and if one you have is, you can temporarily delete it and see if that makes a difference. In that same place where you found how much storage is left on the device, you can select to manage storage and see what apps are using the most of your storage.
