Audio out of sync
 

Quite a nut to break here.
I just reinstalled my system (XP) and my movies are slightly out of sync with the audio. At least I believe so. Maybe the video is out of sync with the audio, but whatever - it's pretty much the same. It only happens with mp4 files, or more like, stuff I made into x264. Rest is fine.
This might not be the best place to ask, but I don't know about any other, so hopefully someone will give me a hint or two...
What I use is 2.27 BSP and latest (4th may) build of FFDShow.

And the filters used by bsplayer are? (with the movie playing -> right click -> Options -> Filters -> Advanced)
I don't think your PC is too low on specs to run flawlessly your movie streams, but it's hard also to think of all your movies to be out of sync in first place.
There's a feature in BSplayer that can help you, by pressing SHIFT+CONTROL+Left/Right you can correct audio delays, but if your movies are not bad-synced, I think you should find the culprit and eliminate it

Yup, they are being used.
Even more weird, other movies are ok. But this one... I don't get it at all!!
Pre-reinstall it was ok.
I'll try re-encoding, but... jeez.

Btw. In options there are several possibilities to choose from in the audio output device - does it matter what I pick?

This is definitely not needed. If the movies are out of sync, you should determine the delay value. Then use MkvToolNix to remux the files with corrected delay. I don't know if you can do that with mp4box.

Well I am more interested in what the heck is wrong... I mean the player is same, codecs as well and the movie too!

Well, the first step would be to determine whether the movie is bad, or the codec setup. Try playing your MP4 on another computer, or at the very least VideoLAN Client.

same problem here
 

I have the same problem as reported above. I believe the problem started after I made the mistake of doing a repair install on my Windows XP installation. (A repair install doesn't reinstall windows, it just reinstalls the important components of windows so that you can boot Windows without losing your programs and settings.) Anyway turns out it was an unneeded repair, one that broke more things than it fixed. MP4 videos have never been in sync since on my BSPlayer. I have to watch them in other players to get them to work, or watch them on my laptop.

I've tried a number of things but to no avail.

I'd dearly like to fix this. I like BSPlayer and would like to be able to use it.

I have BSPlayer version 2.51

Thank you.

Use CTRL + SHIFT + left/right arrow to sync.

Subs are still out of sync. There must be a more practical fix.