To reproduce:
1. Change the keyboard layout to Czech
2. Run the builded project from the attached folder (it contains projects builded with 4.3f3 as well as 4.2f4)
3. Try entering different symbols
4. Try entering different symbols to the notepad or other program to see the difference.

Same happens with different keyboard layouts. 4.2f4 build doesn't allow entering language-specific symbols, however, it also doesn't allow entering numbers from the top of the keyboard even when the english keyboard layout is selected (you have to enter numbers using a separate numpad which is usually on the right of a keyboard).