Windows 8.1 64 bit/Comodo Sandbox

I’m currently using Windows 8.1 64 bit and sandboxie shows error after error due to Windows 8.1 being new and the author of sandboxie trying to fix this. How secure is Comodo sandbox (fully virtualized) for Windows 8.1 - I understand that there is reduced protection for 64 bit systems is this the case for Comodo???

Hope you all had a GREAT New Year and have a safe 2014!!!