IOS email works on IOS 6.1.4 (iphone 5) but not on IOS 6.1.3 (iphone 4)

IOS email works on IOS 6.1.4 (iphone 5) but not on IOS 6.1.3 (iphone 4)

MFMailComposeViewController *mailcontroller =
[[MFMailComposeViewController alloc]init];
[mailcontroller setMailComposeDelegate:self];
This is what I used in my code to set up the email object. It works fine
on iphone 5 but it forces an exit on iphone 4. Please help!