OK, since updating to Mavericks I now find that The Witcher Enhanced edition does not work anymore, anybody know if this can be fixed ?

EDIT: Do not know what happened but it has started working again, I did nothing.

What do you mean by "does not work"? Is the game not loading at all, or Is it loading, then crashing with an error like "Page Fault", or something else?

FWIW I've only used the game on Mavericks and it played fine for a while, then started crashing with Page Fault errors. I ended up updating the WINE wrappers engine as described here:

http://www.reddit.com/r/macgaming/comments/s2bqz/howto_update_the_witcher_enhanced_edition_engine/?sort=new

to the newest version at the time (WS9Wine1.7.18).

It now runs solidly for hours, but I do get the occasional crash, usually after I change a game option, like screen resolution. I hope this helps. It's a great game.

Thanks for this I will certainly try this if I start to get issues.