As reported in https://bitbucket.org/javafxports/android/issue/13/backspace-doesnt-work-in-textfield, the backspace button appears not to work in the SoftwareKeyboard. The reason for this problem is a wrong mapping in android.h. The following patch is for the other vm on android. The dalvik port uses another file, were the same change must be applied.

diff -r 66ce8d7e79b2 modules/graphics/src/main/native-glass/lens/android/android.h
--- a/modules/graphics/src/main/native-glass/lens/android/android.h Tue Dec 24 11:47:11 2013 +0100
+++ b/modules/graphics/src/main/native-glass/lens/android/android.h Wed Dec 25 04:07:39 2013 +0100
@@ -176,7 +176,8 @@
     {AKEYCODE_DPAD_DOWN, KEY_DOWN},
     {AKEYCODE_PAGE_DOWN, KEY_PAGEDOWN},
     //{AKEYCODE_INSERT, KEY_INSERT},
- {AKEYCODE_DEL, KEY_DELETE},
+ {AKEYCODE_DEL, KEY_BACKSPACE},
+ {AKEYCODE_FORWARD_DEL, KEY_DELETE},
 };
 
 #endif /* ANDROID_H_ */