As noted by 9 to 5 Mac, Apple has seeded yet another new build of Mac OS X 10.6.4, this one termed Build 10F564, to developers for testing. The new version carries a mysterious increase of 506 numbers since Build 10F58 released one week ago, although it is possible that the new number is the result of a typo and is meant to have been a more reasonable 10F64 number.
Regardless, the new build continues to list no known issues in the update and carries no documentation in its seed notes of additional changes since the last seed. Developers are once again asked to focus their testing on Graphics Drivers, SMB, USB, Voice Over and VPN.