Pistol -
Sounds like the Sony A700 images you have are not regular uncompressed ARW raw files but cRAW compressed ARW files? The shots of my camera look like what you are seeing but only the arw files shot with the cRAW setting in the camera. If you don't otherwise need what is in DCRCU 2.2 then go back to the previews raw support on your system -
Delete the file: System/Library/CoreServices/RawCamera.bundle then (re)install the previous version.
Get the previous version here:
http://www.apple.com/support/downloads/digitalcamerarawcompatibilityupdate21.htm l
Scintilone -
Are you downloading by connecting the camera directly via cable? If so, remove the media card and put it in a reader. See if that works better for you. It has for others with Nikons....