On my SB3 wired unit, a hang/freeze/lockup happens (very reproducible) if I:

1) start playing any MP3
2) hit >> (ffwd) in web UI (fishbone), wait a few seconds
3) hit << (rev) in web UI (fishbone), wait a few seconds
4) hit play in the web UI

The player is now hung: display is frozen, the SB does not respond to ping, holding power button on remote for 5 seconds does nothing.

Restarting slimserver does not help - it just comes up and displays the message that no player can be found (since the SB3 is not responding).

I have to remove and restore power in order to unfreeze it.

Note that not all Web UI skins have >> and << (hence the fishbone example). Also, using the physical remote to try the same thing does not cause a hang.

If done with a FLAC file, the SB3 does not hang, but it does not resume play after step 4 above.

For my tests, I was Using slimserver 6.5b1 - 5376 - Linux - EN - utf8.