Yeah I hate that. Recently I found that XMen first class will not play on my newest Bluray player, what a rip off. Makes me long for the days of VHS when the studios couldn't pull this kind of garbage.
I have an HDDvD player but only because my DvD player died a week after the format was killed and six months before I had gotten my first HDTV. The DvD player I was looking at was $40 but then a spotted a loan HDDvD player on clearance for $25 and it came with an HDMI cable and seven HDDvD discs in the box so I picked that up quick. It still works and I still use it from time to time, but I do think Bluray was the better format just because more data could be put on the discs.