Hi guys. Just like a few of my other blog entries, I'm here to cover the bad news and the workarounds.

1) OSX will desync with other operating systems if playing the Blizzard map (used by the CTF_Blizzard mission as well).
Fix?
Download:
http://hedgewars.googlecode.com/hg/share/hedgewars/Data/Maps/Blizzard/ma...
http://hedgewars.googlecode.com/hg/share/hedgewars/Data/Maps/Blizzard/ma...

And place those in /applications/games/Hedgewars.app/contents/resources/hedgewars/Data/Maps/Blizzard on the OSX machine.

2) Snow and Christmas themes, and maps that use them, will crash if Reduce Quality is all the way to the left, due to flakes not being optional on those themes. If possible, increase the Reduce Quality slider by 1 to the right. If not possible and you are able to do your own build, I can provide a patch against 0.9.15. Basically amounts to applying:
http://code.google.com/p/hedgewars/source/detail?r=e73707bb99c006db16ae6...
Another workaround if you want to try these themes and must use maximum reduce quality is to create a scheme with a border. This will disable snow.

3) CTF Blizzard map, as well as suffering from (2) will also crash if the Reduce Quality slider is 1 to the right of far left. Fix is to either increase it 1 more to the right or download:
http://hedgewars.googlecode.com/hg/share/hedgewars/Data/Maps/CTF_Blizzar...
and copy it to your local Data/Maps/CTF_Blizzard directory.

Oh, and looks like http://hedgewars.org/node/2598 still applies