Version 3.55.01 introduces kernel-mode protection for 64-bit Windows. With the new Experimental Protection mode enabled, 64-bit Sandboxie is effectively as secure as 32-bit Sandboxie with only a couple of small differences.Experimental Protection enables protection from kernel mode for IPC objects and named named pipes, just like in 32-bit Sandboxie.
To enable Experimental Protection, open the Configure menu in Sandboxie and select the new option, then restart your computer.
Note that Experimental Protection uses an undocumented Windows feature, and as such may be rendered obsolete by some future update to the Windows Kernel Patch Protection mechanism. Such a possible update might cause system instability and BSODs, so enable this new feature at your own risk.
Dieselman,
we have an update thread for this kind of information. 
http://forum.avast.com/index.php?topic=9671.0
Not sure, if this has been posted there already…
Sandboxie, continues to strive for perfection. It’s developer, Tzuk, tirelessly, produces a product, that is far superior to any other. A one man band who has earned the respect, of everyone who realises the power of his creation.
Anyone who is not using S.B is missing out. 
Yours sincerely FANBOY ;D
Yes, I have posted it a couple of hours ago.
Good.