Step to Reproduce:
----------------------
1) Run the attached program.
2) Click on the TextArea. You can see the cursor in the textarea either at the first or last of the text. If cursor is at the beginning press 'End' key. If cursor is at the end press 'Home'key. If you see cusor mark either at the first or last then bug is reproduce.

I have attached a screen shots of the same.
I tested this on Vista beta2 (build 5342) on Mustang b81.