iPhone 4S iOS 6.1.2 Settings -> General -> Keyboard -> Add New Shortcut not case sensitive My custom shortcuts are not case sensitive (the opposite was claimed here).
Example:
Under Settings -> General -> Keyboard -> Add New Shortcut
I specify:
ME : Schorsch
Unfortunately, both ME and me in the text will be replaced with Schorsch. Clearly, the custom shortcut is not case sensitive.
How/where can I fix this?
It's not the Shortcut which is case sensitive, but the Phrase. And I don't think making the shortcut so is possible. And here's a reason why. If you enter in the phrase section a sentence, or a word, in lowercase, the way you use the shortcut will define the way the phrase will appear. Lets clarify this a bit.

Having the shortcut me: whatever, writing Me will be replaced with Whatever, and writing ME will be replaced with WHATEVER, and, of course, me with whatever. 

This won't work if you've used any capitals in the phrase section, which, therefore, makes a point.