Can not re-create the NvFBC object when the 3D games is running?

When I run a 3D game in a virtual pc(win7),the 3D game will change the desktop resolution,so I release the Nvfbc object and try to recreate it,but the status.bCanCreateNow will be false until the game exit or switch to desktop?

Does anyone can help me?

I saw these in the doc:
Boolean that is TRUE if an NvFBC object can be created from the calling process, FALSE otherwise. This field may read back as FALSE for one of the following reasons:
? The calling process is running with insufficient privileges (login screen / session 0, for example). See section Error! eference source not found… ?
A different application is running in full screen mode on any head.

But,many games will change the desktop resolution at the begining,there will be a heap leak if you do not release nvfbc object and recreate it.