XCode 6.2, Unity 4.6.3f1, though the same issue has occurred on multiple builds of 4.6.2 and the latest 4.6.4. After setting all the splash screen images, the screen looks fine on every iOS device with the exception of iphone 4 and 4S. ipod touch 4th gen is also fine. On the 4th gen phones, the screen appears to be either stretched vertically to iphone 5 res, cutting off the bottom of the image, or it’s just using the 4" iphone 5 splash and rendering it at 640x1366, still causing the bottom of the image to be cut off.
I got a tip that setting the default “Mobile Splash Screen” to “none” would get around this bug, but no luck for me. So I tried setting the splash screen for EVERY phone to the 640x960 image used for iphone 4. Building that had the same result as always, leading me to believe it must be stretching that image vertically, why you doing this to my life, Unity!? 
Please submit a bug report and send me PM with case number.
Done and done. case number is 688459
Hi thanks, I will investigate it in the morning.
Any update on this? I’m not sure how quickly you guys process bug reports?
I am having a splash screen error as well, my game is landscape right and the custom splash screen loads then gets flipped upside down after about a second. Doesn’t happen with Unity standard splash only a custom one. I just opted to publish with no splash
I suppose that’s a no? What happens with these bug reports once we toss them out into the ether? Maybe I’m not just paranoid about sending in entire projects as a bug report…
I’m having this issue on two separate projects also, both set to portrait-only orientation in the editor. I did a little digging around in the SplashScreen.mm code, and it looks like it’s picking the iPhone 6+ screenshot which gets scaled down to iPhone 5 size on the iPhone 4S (other devices all work fine). This might only be affecting phones upgraded to iOS 8 too, as it goes through a section of code gated by _usesLaunchScreen where the comments talk about iPhone 6+, and it looks like there’s separate branches for iOS 7 devices.
Unity 4.6.2p1, Xcode 6.3
iPhone 4S, iOS 8.3
Seems to pick LaunchImage-800-Portrait-736h@3x.png
try upgrading to p3 it has so far worked on an ipad for me using unity5
I upgraded one of my projects to Unity 5.0.1p3 due to other unsolvable bugs in Unity 4. That fixed the other bugs, but I still have this issue with it picking the wrong splash screen image on an iPhone 4S with iOS 8.3.
On iOS 8 there is no more device specific splashscreens. Everything is served by single Launch Screen, which essentially means you should stick with one image for all devices. Unity exposes several options how to approach that in Player Settings. Also there is option to disable that by setting Launch Screen to “none”. But in this case your app would lose optimized for iOS 8 and iPhone 6 badge in App Store.