i have used 3110c for 4/5 months before selling it and buy e51. while using 3110c i never had a single problem. its a fantastic phone for below 5k. good sound quality while on call, very good quality sound when using headphone,amazing battery life!,very hardy(many times it fell from my hand)browsing speed also good, I mean while using a i just had no problems whatsoever.But as i felt like buying a new one and already had 6233( which is ofcourse better than 3110c) so just sold it.
Go ahead and buy ! u wont regret
( maybe what ur friends told was a fault with some particular sets, not for the model)
goodluck!