Post the logcat, go to the terminal.. Type the directory /home/xyz/andorid -sdk-xxx/tools
once in this directory. type ./abd logcat
if you are in windows, direct via command prompt to tools directory. Type adb logcat on command line.
do this after you have started the emulator. Once the emulator is running you will see the logcat printing data every time something happens on ur emulator/device (whatever is running).
Now change the orientation and you will see data being printed onto the logcat.. When the app crashes, normally a message will be printed... In my advice you copy all that and paste it here, or better, just paste your code here. Only then can we help...