What techniques for disk, volume and file system management are possible with OS X, but troublesome within Disk Utility?
Things not within a logical volume group (LVG) appear to be within the LVG

Affected: some applications of Core Storage, including but not limited to FileVault 2 in Mountain Lion.

Example

Disk Utility 13 (426) in Build 12A269 of OS X 10.8: 



Volumes swap and spare are JHFS+ and truly not within the LVG. 

disk0s3 is an Apple_Journal, currently unused and truly not within the LVG.

Disk Utility misrepresents all three as being within the LVG.