How to disable Mac OS shortcut on Parallels 8

I'm a user of Parallels 7.
Now I'm trying Parallels 8 for upgrading.

Anyway, I have a problem using Parallels 8 with Windows guest os.

In Windows guest os, I am using SHIFT+Space key for keyboard language change between English and Korean.
And I also using this key combination in Mac OS X to change between English and Korean.

So, when I used Parallels 7, I unchecked the option 'Parallels>Preference>Shortcuts>Enable Mac OS X system shortcut' to disable the propagation of Mac OS X shortcut to Windows guest os. And I also unchecked 'SHIFT+Space ---> Select Language', 'Cmd+Space ---> Select Language' items in Windows key mapping profile.

But, I can't find the option 'Parallels>Preference>Shortcuts>Enable Mac OS X system shortcut' in Parallels 8.
And I can't uncheck 'SHIFT+Space ---> Select Language', 'Cmd+Space ---> Select Language' items in Windows key mapping profile. (This items are displayed in gray so I can't modify the check state)

So, I can't make keyboard language change in Windows guest os.
Sure, if I change the key combination then the problem is solved. But I don't want to change the key combination because it's familiar to me.

How can I solve this problem?