I have the 20120717 version of the firmware running on my i62HD.
I've tried to use a stylus from the Sony PRS-950SC which has the same touch screen technology and the screen appears to barely recognize the presence of the stylus. It appears the software driver is configured to recognize only large objects such as fingers and not thinner objects such as a stylus.
In handwriting mode the stylus is recognized for a short period of time so you get a partial line and then the screen stops recognizing the stylus probably thinking it is invalid input.
Using a stylus is necessary in order to be able to place highlighting accurately and for the handwriting features of the i62HD.
Please let me know how I can go about getting this corrected.