I have to apologise for getting your hopes up. I've spent the past half an hour checking every source of DVD hacks that I know of, without success for that model. Sorry :-(
Perhaps you could relegate your existing DVD player to bedroom use (or flog it on eBay) and buy a new region-free player for £19.99, post free. Then, when kind-hearted relatives send you and your son DVDs from overseas, you'll always be able to watch them:
http://tinyurl.com/2uz7dzj
Chris