This is a response I got back today from Sony customer service. I guess they won't just come out and admit the problem, but from looking at prior reviews it seems that they are trying to fix it.
Thank you for contacting Sony.

It has come to our attention that some Sony DVD players are
occasionally experiencing unsynchronized audio and video when playing
certain DVD titles. Sony is currently conducting tests of the affected
units and titles at several Sony facilities to determine the cause of
the A/V synch condition.

Please e-mail us with the titles of the specific DVD movies which are
causing the lip-sync condition, as this will help us in finding a
solution.

Once Sony has determined the cause we will contact you with a
solution.

Sincerely,

Sony Internet Department

plb

i`ve had my sony dvps550/b for 3 weeks now have version 1.5 software,so far all looks good.i took back a samsung 709 as it would not play layered disks,callled samsung and they know it wont play these disks ,Check out all the reviews it seems like all the dvd players are having problems with lost in space ,lip sync.Have watched about 30 movies with the sony with no problems yet.It seems none of these players have been toataly perfected.also own a toshibia 2109 also a good machine i bought the sony for the DD-ac3 decoder.The remote works great!Yes backlighting would be nice.the speed frim the moment you insert the disk to a picture on the screen is outstandig.slow mo foward AND reverse is rock solid.previewed it at best buy , they change their prices daily 479-449-499-447 never the same price 2 days in a row.Ibiught mine at costco for 399 with 5 free movies 10 free rentals @netflix.overall this machine is outstanding!!

i have owened the s550d for two weeks i have it hooked up to a 32 inch proton tv i can't find one flaw in this unit the picture is astounding, the sound is perfect. i think most problems people have is the tv they connect to.the remote is as good as it could be. as you can see i am very happy with it. highly recomended!

After about 10 movies I began getting the sync problem. After the problem started, I would get it on every movie about midway through. Great player and great features otherwise. I returned it to CC and purchased the DVP-C600D. I'm so glad I made the switch. After about 20 movies still no sync problem, and I don't expect any. This thing has duel lasers. What I like most is having five movies or DVD music videos and switching between them.

I owned this DVD player, but the lip syncing problem prompted me to take it back and purchase a new dvd player......I'm looking either towards Pioneer Elite or Toshiba. Sorry Sony!

I bought this player a couple of weeks ago. I loved it for the most part for the first 8 days. Then it hit. The a/v sync problem!! I have had it twice now. It's going back till Sony can fix this annoyance. Otherwise, I'm buying a different brand.
Very upset. I'd give it 4 or 5 stars if it wasn't for the sync problem.

I have a 550 that I bought in April. Had the A/V sync problem in 1 in 5 discs. Returned it to sony service. Received it back in 2 weeks (I live in CA, DVD repairs occur in Dallas, TX) According to the work order, it had an EPROM IC replaced and the operating firmware upgraded to 2.1. So far so good the first 10 movies I have watched have had no A/V problems. Sony was not surprised when I called them and they told me on the phone that the repair was done form a TSB (technical service bullitin). I'm now completely satisfied with my 550.Andy

How can you people ritually give this product a five star rating? The poster below had to ship a brand new machine to Dallas and wait for two weeks to get it back and still gives it five stars!? This further discredits anything that you say that might even be legitimate. I highly recommend anyone that reads any reviews in this forum to test and listen to equipment for yourselves and take these reviews lightly. No product is perfect and to give a product that has been as problematic as this sony unit five stars is absurd. I know several individuals that own this machine and tey have all encountered this problem. Sony has been and will continue to be very irresponsible if people allow them to produce crap and give them praise for it. Face it you bought a machine that has been poorly designed in hardware and software features. For them to release this DVD player with its problems is unforgivable. Poor unsuspecing folks like yourself fall pray to them and then you turn around like a bunch of wimps and praise the products. I give this unit two stars otherwise would give it four but they released this thing prematurely.Wise up give praise where it is due.

I bought this truly excellent player after the new batch of machines were distributed. Or so I thought. I saw my first errors last week in the Anniversary edition disc of Taxi Driver (dual layer). I called Sony to ask about fixes, and the very helpful Tony took my name, asked a lot of questions about hook-up, title, etc, and said that they were still investigating the problem and that they would contact owners when a fix was ready. I urge everyone with sync problems to call Sony at 800-222-7669, then press 1, 4, 3 to skip through recordings and get a customer service person. I hope this gets fixed soon.
It really is a great machine, however. I have recommended it to friends and family, with the caveat that the a/v sync san be an issue.

I would give it five stars, but only five-star players with no problems really _deserve_ five stars.

Well, after months of dealing with the sync problem and going thru 3 different players, I finally decided to give up on sony and go for the Pioneer Elite DV-05 THX. I just got really sick and tired of dealing with sony and not getting straight answers. Even though I know you can send your player in and get a new chip put in, I didn't pay all that cash for a factory refurb. I also didn't want to wait until the "fixed" units actually started showing up in stores. The sony had alot of strong points and it's a great player, but like I said before way too many headaches dealing with the 550D.