Trouble with the custom font on Java, Android

I use the custom typeface and app in emulator API version 2.1 (and my mobile API version 2.1) work correctly, but in older versions app don't work with Exception:

08-04 06:16:14.041: ERROR/AndroidRuntime(273): Caused by: java.lang.RuntimeException: native typeface cannot be made

I use this code:

Typeface t=Typeface.createFromAsset(mAssetManager, "fonts/MusiSync.ttf");

But I need all version for my 开发者_Python百科app. Help me please. Thank you for, anyway.

Check this out:

http://mobile.tutsplus.com/tutorials/android/customize-android-fonts/