Philips dvp 642- can I flash to older firmware?

I am getting another 642 and I want to use the older (531 I think) firmware, as I have heard the new one has problems. Has anyone flashed backwards with no problems?

Thanks in advance

I checked with Videohelp and it looks like the answer is maybe.

I could swear my 642 used to play raw MPG files off a DVD before. I upgraded to the new one (came out in November 2004) and I can only play some of them now. Did they remove some codecs?

Yes, you can flash backwards.