I've got the mac demo version but I can't set a mark with command-space (or ctrl space). It originally brought up the spotlight window but have now changed that shortcut. But still doesn't set the mark.
Glad you found the <cmd /> for now. I am not very happy with this but <cmd space> is reserved for "Spotlight Search" at least on my Mac so I had to avoid clashing with that. There are a lot of small differences in the Mac version because there are so many built in OS level key commands.
If you have any thoughts on better ways to set this up, I am all ears. I have seen some applications (games) that manage to avoid these key commands but I have no idea how they did it right now.