I also suffer the same problem when my Internet slow down You will suffer the problem if you play on 2g or 3G with low bandwidth
You can try clearing cache, history and temp file. I use battery doctor pro for it as it include sb setting features too
Not even a factory reset will do it, maybe jailbreaking you can but Id never suggest that to anyone, it causes nothing but problems.
I have iphone 5 and still have the same problem. I thought it was because my phone was jail broken but usually after a restart it tarts acting right.
I have an iPhone 4 too and it's updated and everything I only have that problem cuz sometimes the internet sucks in my room so it gets slow but for 3G and when I'm in an area where the internet reaches normally it works fine for me.
I was talking to support and they said there was a lag in the iOS system, but it has been resolved. Though you could still experience the effects of it. They said to either reset your network connection or uninstall an reinstall the game. Neither one worked for me. .__.