When was a patch released ?? And is it only for Steam versions ??
Yes it was a Steam patch, and from what they say, it appears this Steam patch introduced the save game bug. They say it's been fixed in an even newer patch.
The DRM-free Humble version of the game had a notice that said the DRM-free version would never be patched. So you (Mad) shouldn't get the problem.
Here are some quotes:
There is a major issue found in the last patch where people's save files are being deleted. I've reverted the patch, but if you have played in the last 30 minutes, you save file may have been affected.
Let me know here if this has affected you and I'll work on getting you your progress back!
So anyone with the Steam version whose save disappeared may want to contact Falco for help getting their save back.
We apologize that this save bug slipped past our nets on the latest patch. It was an oversight and we have since reverted it. (So if you are reading this and haven't played, make sure you get the very latest update)
If you are having this problem and can describe to us exactly where you are in the game, we can recreate a save file for you in that location, so you can just load that instead of having to do everything over again >< Please email us at firstname.lastname@example.org with where you last were, including any runes you may have picked up, and we will email you a save that should be close to that!
Quotes are fromhttp://steamcommunity.com/app/299400/discussions/3/1519260397776663390/
I downloaded the non-Steam version of Xing from Humble Bundle as soon as it became available and burned it to disk.
You may want to back it up some other way, or at least check that your burn is OK.
The XING_The_Land_Beyond.zip file was a huge file (over 4 GB in size), and my attempt to burn it failed because of the extremely large size of the file. When I tried to extract the game from the XING_The_Land_Beyond.zip file on the DVD, it extracted files, but said the zip was corrupt. It extracted a huge number of files into folders and subfolders so it was practically impossible to check what may have been missing or corrupt. I've now backed the game up on a USB drive.
Anyway, your burning software might work better than mine, but you may want to check that the XING_The_Land_Beyond.zip file on your DVD doesn't produce an error while extracting.