Divx files lose aspect ratio when played at full screen

[Speed Racer]

I just installed windows xp and now my divx files (and just the divx files) wont play at the correct aspect ratio anymore (and yes, keep aspect ratio is checked on in my players). The divx files keep the correct aspect ratio when played at 50%, 100% & 200%, just not at full screen mode. I had a similiar problem when I was using win2k but my ati media player would still play the divx files at the correct ratio even at full screen so I just used it instead of other players (windvd, powerdvd, etc...). Well, now even my ati media player won't play at full screen with the correct ratio!
Anyone have or hear of such a problem??

[Speed Racer]

Thanks for the replies! I guess I resolved my problem last night. I installed the latest windvd player and it keeps the aspect ratio at full screen (though powerdvd and ati player still doesn't). I also should have been more clear in my initial post. I only had a problem with the media players that could output ac3 sound. The divx.com player would play my divx files fine at full screen but I don't use it since it can't ouput ac3 sound.
Thanks again!