I've captured some .mkv files with Simple Screen Recorder (SSR). When I watch these individual files, they play fine in Mplayer. The sound and image are in perfect sync. I hear clicks from my mouse and they match with actions on the screen.
While editing (A/V Sync is on) in Blender's Video Sequence Editor (VSE) it all seems rather fine - I can not play it back smoothly from Blender (640x480@60FPS, h.264 losless, stereo FLAC audio), but it doesn't seem to float too much. Just a little, especially when I start in the middle of a clip.
I rendered the movie, and the sound is completely off with timing in relation to the motion picture. It's floating around by a couple of seconds (an event happens, a few seconds later I hear sounds that were related to the event I saw earliest etc.).
I tried re-rendering the movie after enabling and generating timecode (Free run mode) for all movie clips. It didn't help at all.
What is happening? Is this a bug? I'm having these sync issues for years now.