Lighroom Produces DNG's 2x the Size of SRAW1 files for Canon 5D Mark II

So this afternoon I finally addressed something
I have noticed when processing SRAW1 files from my Canon 5D Mark II. 
SRAW1 files are being converted to a DNG file
that is almost twice the size of the native CR2 (RAW) file in Lightroom
v2.3. 
This is a huge filespace premium to pay for maintaining my archive in
DNG.  A quick search of Google turned up nadda.

Also annoying but minor, CR2 and DNG SRAW1 files display as an image
with 0 x 0 resolution, and no preview image is displayed in Finder in
MacOS v10.5.6

Here's the down and dirty:

Original Canon 5D Mark II SRAW1 .CR2 file: 10MB

DNG, no JPEG Preview, Preserve Raw Image, Uncompressed: 57.2MB
DNG, no JPEG Preview, Preserve Raw Image, Compressed: 18MB

DNG, no JPEG Preview, Convert to Linear Image, Uncompressed: 57.2MB
DNG, no JPEG Preview, Convert to Linear Image, Compressed: 24.9MB

DNG, no JPEG Preview, Preserve Raw Image, Uncompressed, Embed Original RAW file: 66.4

Update 5/13/2009 @ 5p: According to this post in Adobe Forums, "The sRaw format is not covered by the DNG specification. When
converting, it must be changed; in fact, the amount of data needs to be
increased by 50%."